Lake Kuttara and Noboribetsu
The third member of this caldera lake trio is the much smaller Lake Kuttara. It lies roughly halfway between its bigger siblings and slightly to the south. It is round like Lake Toya, but has a diameter only a quarter of the size. All of these lakes were created in the same way: by volcanic activity. Noboribetsu, one of the best-known onsen hot spring resorts in Hokkaido, is located nearby. It features the long Jigokudani (Hell Valley), where you can walk on a raised boardwalk over an otherworldly whitish landscape almost devoid of vegetation but replete with boiling pools of water, bubbling mud, and wisps of steam rising from the ground.