Den Blå Planet – National Aquarium Denmark

An underwater world on the edge of Copenhagen

Den Blå Planet rises on the Kastrup shoreline like a swirling seashell, its flowing metal cladding hinting at the currents and tides inside. Designed to resemble a vortex in the sea, the building pulls you naturally towards a central hub from which all the exhibition wings radiate. Just beyond the glass, the Øresund stretches towards Sweden, reinforcing the sense that sea and aquarium are directly connected. Inside, soft blue light, gently curving walls and the quiet hum of filtration systems replace the bustle of the city. From the first steps down into the exhibition halls, you are surrounded by water on multiple levels, with tanks wrapping around corners and stretching above your head. It feels more like entering a self-contained marine world than a conventional museum.

Ocean tank drama and northern seas

The heart of the aquarium is the vast Ocean Tank, holding millions of litres of seawater and home to hammerhead sharks, rays and schooling fish that glide past a panoramic window several metres high. A transparent tunnel runs through part of this realm, giving the classic thrill of watching large animals sweep silently overhead while smaller species weave around in dense, glittering shoals. Nearby, exhibits inspired by the cold northern seas showcase life from the Danish coasts and the broader North Atlantic. Here you encounter cod, flatfish and jellyfish, but also rocky habitats and kelp forests recreated in careful detail. Touch pools allow you to feel the rough carapace of a crab or the smooth skin of local species, tying the dramatic displays back to the everyday waters that surround Denmark.

Rainforest heat and global habitats

One wing of Den Blå Planet swaps Nordic chill for tropical humidity. This rainforest zone wraps you in warm, moist air, the sound of dripping water and birdsong, with lush planting around tanks of brilliantly coloured freshwater fish. Here you might see archerfish spitting jets of water at insects, cichlids defending territories, or reptiles basking under dappled light. Interpretive panels and models link each habitat to a wider geography, turning the aquarium into a journey between continents. From Alaskan seas to Indian mangroves and African lakes, the galleries highlight how different ecosystems are connected by currents, climate and human impact, positioning the aquarium as both an attraction and an informal classroom.

Sea otters, rays and close-up encounters

Outside, the focus turns to some of Den Blå Planet’s most charismatic residents: sea otters. These energetic marine mammals twist and tumble through the water, playing with enrichment toys and pausing to groom their dense fur on the rocks. Feeding demonstrations reveal how much food such small animals consume each day and explain how rescued otters have found a permanent home here. Back indoors, cownose rays glide in a shallow display where supervised feeding sessions allow children and adults to watch them using finely tuned senses to locate food. Piranhas, giant arapaimas, and other crowd-pleasing species are introduced through scheduled talks and feedings, punctuating a visit with moments of drama and expert commentary.

Architecture, learning and day-out comfort

Beyond the tanks, the building itself remains a highlight. Seen from above, its spiral plan radiates like a whirlpool; at ground level, long curving corridors frame sudden, carefully staged views into enormous aquaria. Natural light is controlled so that the fish remain in focus, while subtle seating niches offer places to pause and take in the spectacle. Practical touches make it easy to spend several hours here. Level access and lifts serve all areas, wide walkways accommodate strollers and wheelchairs, and there is a café overlooking the sea along with an outdoor water play area in warmer months. Educational signage, children’s activity points and temporary exhibitions on themes such as underwater photography or climate issues deepen the experience for curious visitors of all ages.

A full-day highlight on the Øresund shore

Located close to Copenhagen Airport yet feeling a world away, Den Blå Planet works as both a quick escape and a lingering outing. Many visitors move slowly between zones, returning to favourite windows to watch animal behaviour evolve over time. Others focus on specific themes, from conservation stories to the engineering that keeps such large systems running. Whether you are travelling with children, exploring solo or combining the aquarium with a walk along the water, the combination of bold architecture, diverse species and hands-on learning makes this one of Greater Copenhagen’s most distinctive indoor attractions, especially welcome on blustery or rainy days by the Øresund.