Private Swap - Japan

Goshiki-numa is a cluster of five volcanic lakes situated at the foot of Mount Bandai in the center of the lake district of Bandai-kōgen, Fukushima Prefecture, Japan.

Goshiki-numa formed when Mount Bandai erupted on July 15, 1888, destroying dozens of villages and killing approximately 500 people while creating hundreds of lakes and tarns. (source)

Thank you Clarissa!