Shima potholes Travel Guide

Located near Shima Onsen in Gunma Prefecture, the Shima Potholes (Shima Ouketsu) are a testament to the power of nature's artistry. Over millennia, the Shima River has sculpted a series of eight potholes into its bed, each a smooth, rounded basin filled with strikingly blue water.The potholes were formed by the continuous swirling of stones and sand, driven by the river's current. This constant erosion gradually carved depressions into the bedrock, creating the unique formations visitors can admire today. The largest pothole measures approximately 2.9 meters in width and 1.5 meters in depth.The Shima Potholes are easily accessible and located close to the main road. Visitors can walk along well-marked trails to view the potholes from different angles and enjoy the surrounding scenery. The area is particularly beautiful in April and May when the river's blue color is most vibrant, and during the autumn foliage season from late October to early November.While access to the riverbed may be restricted during certain times of the year due to weather conditions or dam operations, the Shima Potholes can still be appreciated from the side of the road.