Porth yr Ogof: Wales' Largest Cave Gateway in Brecon Beacons
Explore Wales’ largest cave entrance, a thrilling limestone labyrinth carved by the Afon Mellte in the heart of Brecon Beacons National Park.
Porth yr Ogof is a vast solutional cave near Ystradfellte, Wales, boasting the largest cave entrance in Wales and one of the largest in the UK. Stretching over 2.25 km, this limestone cave system features multiple entrances, underground rivers, and striking geological formations. Once a show cave, it now serves as a premier site for caving exploration and training in the scenic Brecon Beacons National Park.
A brief summary to Porth yr Ogof
- Aberdare, Ystradfellte, CF44 9JF, GB
- Duration: 1 to 3 hours
- Budget
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Outdoor
- Mobile reception: 3 out of 5
- Monday 12 am-12 am
- Tuesday 12 am-12 am
- Wednesday 12 am-12 am
- Thursday 12 am-12 am
- Friday 12 am-12 am
- Saturday 12 am-12 am
- Sunday 12 am-12 am
Local tips
- Wear sturdy waterproof footwear as parts of the cave require wading through knee-deep water.
- Join a guided caving tour or training session to safely explore the cave’s complex passages.
- Avoid the Resurgence Pool area due to its depth and strong currents; heed all safety signage.
- Visit during drier weather for easier access, as the cave can be very wet and slippery after rain.
- Combine your visit with a walk along the scenic Afon Mellte gorge to experience the surrounding natural beauty.
For the on-the-go comforts that matter to you
- Restrooms
- Drink Options
- Food Options
- Seating Areas
- Information Boards
Getting There
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Car
Drive from Brecon via the A4059 towards Ystradfellte, approximately 40–50 minutes. Parking is available at the Porth yr Ogof pay & display car park near the cave entrance. Note that parking fees apply and spaces can fill during peak times.
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Bus
Take the local bus service from Brecon to Ystradfellte, which takes about 1 to 1.5 hours depending on the schedule. From Ystradfellte village, it’s a 20-minute walk along marked trails to the cave entrance. Bus services may be limited on weekends and holidays.
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Walking
For those staying nearby, a scenic 30–45 minute walk from the Waterfalls Centre in Pontneddfechan follows well-maintained trails through the Afon Mellte gorge to Porth yr Ogof. Terrain includes rocky paths and some uneven surfaces, suitable for moderately fit walkers.
Porth yr Ogof location weather suitability
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Any Weather
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Rain / Wet Weather
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Mild Temperatures
Discover more about Porth yr Ogof
A Majestic Entrance to the Subterranean World
Porth yr Ogof, meaning 'gateway to the cave' in Welsh, is renowned for having the largest cave entrance in Wales, measuring nearly 20 meters wide and 8 meters high. Located near the village of Ystradfellte at the southern edge of the Brecon Beacons National Park, this imposing gateway invites adventurers into a vast limestone cave system carved by the Afon Mellte river. The river’s flashy nature, rising and falling rapidly after rainfall, plays a key role in shaping the cave’s dynamic environment.Complex Network of Passages and Entrances
The cave extends over 2.25 kilometers with more than fifteen entrances scattered around the area. The main entrance is typically accessed by a dry ledge or by wading through knee-deep river water, while other notable entrances like the Workman's or Tradesman's Entrance provide alternative access points. Inside, visitors encounter a labyrinth of passages, including boulder-strewn floors, calcite pools such as the White Horse Pool, and underground waterways. The cave is largely wet, with several sumps—completely flooded passages—that challenge even experienced cavers.Historical and Geological Significance
Porth yr Ogof has been known since at least the late 17th century, mentioned by naturalist Edward Lhuyd and explored extensively in the 20th century by pioneering caving clubs. The cave’s passages are formed within Carboniferous Limestone, a geological formation stretching across the Brecon Beacons. The area is rich in fossils and features remarkable calcite veins and stalactites, providing insight into the region’s ancient natural history.A Hub for Caving Enthusiasts and Training
While once operated as a commercial show cave, Porth yr Ogof now serves primarily as a training ground for cavers of all skill levels. Its varied terrain includes crawls, climbs, and water-filled sections, making it an ideal primer for cave exploration. Safety is paramount, as the cave has a history of accidents, particularly near the deep and fast-flowing Resurgence Pool. Guided excursions emphasize the cave’s unique features such as Hywel’s Grotto, a chamber adorned with calcite formations and pools.Natural Beauty and Conservation
Surrounded by the lush, fern-covered gorge of the Afon Mellte, the cave lies within a Special Area of Conservation and a Site of Special Scientific Interest. The area’s magical atmosphere has attracted filmmakers and nature lovers alike. Visitors can appreciate not only the subterranean wonders but also the scenic landscapes and wildlife of the Brecon Beacons National Park.Visitor Experience and Practical Details
Exploring Porth yr Ogof offers a blend of adventure and natural history. The cave’s large entrance and accessible passages make it suitable for beginners accompanied by experts, while experienced cavers can delve deeper into its maze-like network. The nearby Waterfalls Centre provides visitor facilities, and the surrounding trails offer opportunities for hiking and wildlife observation. The cave’s wet and sometimes challenging conditions require appropriate preparation and respect for its natural hazards.Iconic landmarks you can’t miss
YHA Brecon Beacons
11.0 km
Rustic farmhouse hostel offering clean, cozy accommodation and a warm communal atmosphere in the heart of Brecon Beacons National Park.
Cantref - Adventure Farm in South Wales
18.5 km
Experience family fun at Cantref Adventure Farm in South Wales, where children can connect with animals and enjoy exciting outdoor activities.
Aberfan Disaster Memorial
18.7 km
Explore the Aberfan Disaster Memorial, a poignant tribute to resilience and remembrance in the heart of Wales, honoring lives lost in the 1966 tragedy.
Theatr Brycheiniog
19.6 km
Experience the vibrant performing arts scene at Theatr Brycheiniog in Brecon, where culture meets scenic beauty along the canal.
Brecon Canal Basin
19.7 km
Breathe in the beauty of Brecon Canal Basin, a serene escape in Wales perfect for leisurely walks, local cuisine, and outdoor adventures amidst stunning landscapes.
The Promenade
19.8 km
Discover tranquility and natural beauty at The Promenade in Brecon, a perfect park to unwind and enjoy the stunning Welsh landscape.
Gate Gallery & Glassworks
19.8 km
Discover the artistic beauty of handmade glassware at Gate Gallery & Glassworks in Brecon, where craftsmanship meets creativity.
Parc Bryn Bach
19.8 km
Experience the natural beauty and recreational fun of Parc Bryn Bach in Tredegar, a perfect destination for outdoor enthusiasts and families.
Y Gaer Museum, Art Gallery & Library
19.8 km
Explore Y Gaer Museum, Art Gallery & Library in Brecon for an enriching experience of local history, art, and literature in a cultural landmark.
Duke of Wellington Monument
19.8 km
Historic bronze statue honoring the Duke of Wellington, a commanding presence in Brecon’s town centre and a testament to local artistry and British heritage.
Brecon Town Tours - guided history walks
19.8 km
Experience the rich history of Brecon with guided tours that unveil the town's hidden gems and captivating stories in the heart of the Brecon Beacons.
Brecon Barracks
19.8 km
Historic military hub in Brecon, home to the Royal Welsh Regiment and its museum, set within the stunning Brecon Beacons National Park.
The Brecon Castle Hotel
19.8 km
Historic Wales’ oldest hotel blending timeless charm with modern comforts near Brecon Beacons National Park.
Brecon Walk Way
19.8 km
Experience the tranquility and stunning landscapes at Brecon Walk Way, a must-visit tourist attraction in the heart of Wales.
The Royal Welsh Regimental Museum
19.9 km
Explore the Royal Welsh Regimental Museum in Brecon, where Wales' military history comes alive through captivating exhibits and rich heritage.
Unmissable attractions to see
Four Waterfalls Walk
1.3 km
Discover the enchanting Four Waterfalls Walk, a scenic 9 km trail through ancient woodland and cascading falls in Wales’ Brecon Beacons National Park.
Sgwd Clun-Gwyn Waterfall
1.6 km
Discover the cascading beauty of Sgwd Clun-Gwyn, a serene multi-step waterfall nestled in the lush woodlands of South Wales’ Brecon Beacons.
Sgwd Isaf Clun-Gwyn
1.9 km
Discover the serene multi-tiered cascades of Sgwd Isaf Clun-Gwyn, a tranquil jewel on the Four Waterfalls Walk in Wales’ Brecon Beacons.
Sgwd y Pannwr
2.2 km
Discover the serene tiered cascade of Sgwd y Pannwr, a scenic highlight of the Four Waterfalls Walk in Wales’ Brecon Beacons National Park.
Sgwd Yr Eira Waterfall
2.5 km
Walk behind the stunning 50-foot curtain of water at Sgwd yr Eira, the enchanting Waterfall of Snow in Wales’ Brecon Beacons.
Sgwd Gwladys Waterfall
4.5 km
Discover the serene beauty of Sgwd Gwladys, a graceful 7-meter waterfall nestled in Wales’ scenic Waterfall Country.
Penderyn Brecon Beacons Distillery - Visitor Centre and Shop
4.8 km
Discover the home of Welsh whisky in the Brecon Beacons – tour the original Penderyn Distillery, see the Faraday still, and taste award-winning single malts.
Dinas Rock
4.8 km
Explore the towering limestone cliffs, ancient hillfort, and enchanting waterfalls of Dinas Rock in the heart of Wales’ Waterfall Country.
Cadair Fawr
5.0 km
Accessible mountain views across South Wales' rolling landscape, perfect for all abilities.
Waterfall Country
5.5 km
Discover the enchanting cluster of waterfalls and ancient woodlands in Wales’ Brecon Beacons National Park, where rivers carve dramatic gorges.
Sgwd Gwladys
5.6 km
Discover the enchanting 7-meter cascade of Sgwd Gwladys, a legendary waterfall nestled in South Wales’ scenic Waterfall Country.
Fforest Fawr Geopark
5.8 km
Explore Fforest Fawr Geopark’s ancient geology, wild landscapes, and rich Welsh heritage in the heart of the Brecon Beacons National Park.
Maen Llia
6.7 km
Discover Maen Llia, a majestic Bronze Age standing stone in the Brecon Beacons, steeped in legend, celestial alignments, and prehistoric mystery.
Ogof Ffynnon Du National Nature Reserve
7.1 km
Explore the UK’s deepest cave beneath wild moorlands and historic ruins in the breathtaking Ogof Ffynnon Ddu National Nature Reserve.
Henrhyd Falls
7.5 km
Discover South Wales’ tallest waterfall with a thrilling walk behind the cascading curtain at Henrhyd Falls in the Brecon Beacons.
Essential places to dine
The Red Lion Inn, Penderyn
4.3 km
A cozy Welsh gastropub blending traditional charm, local flavors, and legendary roasts in the scenic village of Penderyn.
Penycae Inn Ltd
8.5 km
Cozy gastropub in the heart of South Wales offering fine Welsh cuisine, scenic mountain views, and a unique family-friendly atmosphere.
Carnivore By The Mine
9.3 km
A cozy meat-lover’s haven in Neath, blending hearty dishes with heartfelt mining heritage and warm local charm.
Abercrave Inn
10.3 km
A rustic Welsh country inn offering hearty home-cooked meals, cozy charm, and a peaceful rural retreat in Abercraf.
Mango House Restaurant
11.2 km
Experience authentic Indian cuisine with warm hospitality in the heart of Merthyr Tydfil’s Cefn-coed-y-cymmer.
Aberglais Inn
11.8 km
Cozy pub and restaurant in Merthyr Tydfil offering hearty British classics, vegan and gluten-free options, with a warm, friendly atmosphere.
Red Cow Inn
12.9 km
A charming traditional Welsh pub in Pontsticill offering hearty home-cooked meals, award-winning ales, and a warm, welcoming atmosphere.
Rhydycar Harvester
14.0 km
Casual family dining with classic British flavors and welcoming amenities in Merthyr Tydfil’s Rhydycar Leisure Park.
The Pantyscallog Inn
14.1 km
A beloved steakhouse in Pant, Merthyr Tydfil, known for hearty portions, friendly service, and a warm, welcoming atmosphere.
The Tai’r Bull Inn
15.1 km
A cosy Welsh country pub and B&B offering hearty fare, real ales, and warm hospitality in the heart of Brecon Beacons National Park.
The Tanners Arms
15.2 km
Rustic Welsh pub and cozy B&B nestled in scenic Defynnog, offering hearty food, local ales, and warm hospitality near the Brecon Beacons.
Pentrebach House Table Table
15.8 km
Classic British pub dining with family-friendly charm and hearty meals in the heart of Merthyr Tydfil.
Usk & Railway Inn
16.3 km
Cozy country inn with hearty local cuisine and premium comfort near Brecon Beacons National Park.
The White House
16.8 km
A charming country inn near Brecon Beacons offering warm hospitality, fresh local cuisine, and cozy rooms for a relaxing Welsh getaway.
Castle Coaching Inn
17.3 km
Historic Welsh inn in Trecastle offering cozy rooms, traditional cuisine, and warm hospitality near Brecon Beacons National Park.
Markets, malls and hidden boutiques
Kindle House
14.2 km
Whimsical Victorian boutique where curated rooms and creative collections inspire joy and discovery.
The UK Loose Leaf Tea Company Ltd
18.4 km
Discover ethically sourced, premium loose leaf teas and sustainable brewing essentials at The UK Loose Leaf Tea Company Ltd in Brecon.
Hay & Brecon Farmers Brecon
18.6 km
Experience the best of local Welsh produce at Hay & Brecon Farmers Brecon, where freshness and quality meet a warm community spirit.
B&M Home Store with Garden Centre
18.8 km
Affordable shopping meets gardening passion at Brecon’s versatile B&M Home Store with Garden Centre.
Mind
19.0 km
Explore unique finds and support mental health initiatives at Mind Charity Shop in Brecon, where every purchase makes a difference.
CERTAS - BRECON
19.3 km
Discover convenience in Brecon with CERTAS, your one-stop shop for essentials, local treats, and friendly service.
Kitty Keane's Vintage
19.8 km
Discover authentic Welsh vintage and handcrafted treasures at Kitty Keane's Vintage, a charming craft shop in the heart of Brecon.
DIXIES CORNER
19.8 km
Brecon's trusted specialist in authentic military surplus and outdoor gear since establishment.
Bentley & Co Home Interiors & Coffee Shop
19.8 km
Discover stylish home interiors and savor homemade coffee and light lunches in the heart of Brecon’s charming Ship Street.
Bi Ped Cycles
19.8 km
Biped Cycles: Your expert cycling partner in Brecon, offering quality bikes, certified e-bike servicing, and personalized care near the Brecon Beacons.
Dressed To Impress!
19.8 km
Family-run bridal and occasion wear boutique in Brecon offering elegant dresses and personalized service for all body types.
Gibb Outdoors
19.8 km
Trusted outdoor gear and expert advice in the heart of Brecon for all your Welsh adventures.
Beacons Antiques
19.8 km
Discover timeless vintage treasures and unique collectibles at Beacons Antiques, a charming hub of history in the heart of Brecon.
Premier
19.8 km
Your friendly, convenient stop for groceries and essentials in the heart of Brecon, open early to late every day.
Ardent Gallery
19.8 km
Explore contemporary art at Ardent Gallery in Brecon, a vibrant hub for creativity and cultural expression.
Essential bars & hidden hideouts
Drovers Arms
19.1 km
A welcoming Welsh village pub blending historic charm with hearty fare and friendly hospitality in the heart of Llanfaes, Brecon.
The Three Horseshoes Inn
19.4 km
A cosy Welsh village pub blending traditional charm with refined British cuisine and a warm, welcoming atmosphere.
hop in beer and gin
19.8 km
Discover Brecon’s quirky bar with top-quality craft beers, artisanal gins, and delicious tapas in a cozy, historic setting.
The Rorkes Drift
19.8 km
Historic Welsh pub in Brecon offering local ales, lively music, and a warm atmosphere inspired by the legendary Rorke’s Drift battle.
The Sarah Siddons
19.8 km
Experience authentic Welsh hospitality with local ales and lively atmosphere at The Sarah Siddons, Brecon’s beloved town centre pub.
The Lounge Bar & Cafe
19.9 km
Brecon’s pioneering bar with a modern twist, offering signature cocktails, live music, and a welcoming atmosphere in the town centre.
Markets Tavern
19.9 km
Traditional Welsh pub and welcoming hotel in Brecon offering hearty food, cozy rooms, and authentic local charm on Free Street.
Shoemakers Arms
20.6 km
Charming community-run pub in the heart of Brecon Beacons, offering warm hospitality and authentic Welsh cuisine in a rustic setting.
Royal Oak
20.7 km
Cozy Welsh pub in Pencelli offering traditional hospitality and local ales amidst the scenic Brecon Beacons.
The Star Inn
21.1 km
A cozy and characterful pub with quality food and a sunny beer garden in the heart of Talybont-on-Usk, perfect for walkers and families alike.
The Dyffryn Arms
21.9 km
A classic Welsh pub in Neath offering hearty meals, warm hospitality, and a welcoming atmosphere for locals and visitors alike.
Pontardawe Inn
22.1 km
Lively, dog-friendly pub in Pontardawe offering hearty food, real ales, live music, and a warm Welsh welcome in a cozy setting.
Coach & Horses
22.9 km
Historic canal-side pub and inn in Llangynidr offering hearty Welsh fare, cozy rooms, and a warm, welcoming atmosphere.
The Pwllgloyw Arms
23.5 km
A cozy mountain pub in Powys offering hearty Welsh fare, local ales, and a warm, welcoming atmosphere year-round.
The Pennsylvania
23.7 km
A welcoming traditional pub on Briton Ferry Road, The Pennsylvania offers a classic Welsh community gathering spot with a friendly and relaxed atmosphere.
Nightclubs & after hour spots
The Kirkhouse Nightclub (Koolers)
13.2 km
Experience the vibrant and friendly nightlife of Merthyr Tydfil at The Kirkhouse Nightclub, known locally as Koolers.
Pure Bar & Nightclub Ltd
13.6 km
A lively nightclub and cocktail bar in Merthyr Tydfil offering vibrant music, crafted drinks, and late-night entertainment in South Wales.
The Top Club
19.5 km
Experience Blaengarw’s vibrant nightlife at The Top Club, where electrifying entertainment meets community spirit in the heart of South Wales.
Northcote Conservative Club
19.8 km
Discover the lively ambiance of Northcote Conservative Club, Brecon's premier destination for nightlife, music, and local culture.
Brecon Working Mens Club
19.8 km
Experience authentic Welsh hospitality at Brecon Working Mens Club, where locals gather for drinks and camaraderie in a charming setting.
BRECON JAZZ
19.8 km
Experience the soulful sounds of Brecon Jazz, an intimate venue celebrating the rich heritage of jazz music in the heart of Wales.
Brecon Jazz Club (Muse Arts Centre)
19.8 km
Discover the heart of jazz in Brecon at the Brecon Jazz Club, where live music and a vibrant atmosphere collide for an unforgettable night.
The Arch Bar & Nightclub
23.2 km
A lively Neath hotspot blending nightclub energy, live music, pub charm, and Thai cuisine in one vibrant venue.
Squares Night club
23.3 km
Experience Porth’s vibrant nightlife at Squares Nightclub, where music, dance, and unforgettable evenings come alive every weekend.
Jimmy's Bar
27.8 km
Experience the vibrant nightlife and live music scene at Jimmy's Bar, Port Talbot’s lively local hotspot with a welcoming atmosphere.
Eclipse Nightclub
28.4 km
Experience Pontypridd’s vibrant midweek nightlife at Eclipse Nightclub, where music, dancing, and community come alive every Wednesday night.
Popworld - Swansea
33.3 km
Experience Swansea’s energetic retro nightclub with affordable cocktails, themed events, and a lively dance floor in the heart of the city.
PlanB
33.6 km
Swansea’s energetic two-floor nightclub with a focus on dance music, lively DJs, and great drink deals for a night to remember.
Cuba Escape
33.6 km
Experience Swansea’s vibrant nightlife at Cuba Escape, where live music, energetic crowds, and a colorful atmosphere come together for unforgettable nights.
Sin City
33.9 km
Energetic Swansea nightclub with live music, affordable drinks, and a lively atmosphere on Dillwyn Street.
For the vibe & atmosphere seeker
- Adventurous
- Scenic
- Tranquil
- Unique
For the design and aesthetic lover
- Rustic Designs
For the architecture buff
- Natural Landmark
For the view chaser and sunset hunter
- Iconic Views
- Panoramas
For the social media creator & influencer
- Instagrammable
- Photo Spots
For the eco-conscious traveler
- Protected Area
- Nature Reserve
- Public-Transport Accessible
- Leave-No-Trace Critical
- Locally Managed
For the kind of experience you’re after
- Adventure Photo Shoot
- Nature Escape
- Day Trip
- Cultural Heritage
For how adventurous you want the journey to be
- Easy Access
Location Audience
- Family Friendly
- Teen Friendly
- Solo Friendly
- Couple Friendly
- Senior Friendly