Lake Nakatsuna

Lake Nakatsuna (中綱湖, Nakatsuna-ko) is a lake in Ōmachi Nagano Prefecture, Japan. It is one of the "Nishina Three Lakes" (Lake Aoki, Lake Nakatsuna and Lake Kizaki).^[3] Its sediments have been studied in an effort to better understand climate change in Japan, finding evidence of the Medieval Warm Period and Little Ice Age.^[1][2]

Lake Nakatsuna
Lake Nakatsuna in winter
Lake Nakatsuna
Location	Ōmachi, Nagano, Japan
Coordinates	36°30′N 137°51′E
Lake type	Eutrophic lake
Surface area	12.5 hectares (31 acres)[1][2]
Max. depth	12 metres (39 ft)[3]
Surface elevation	820 m (2,690 ft)
Settlements	Near Omachi, Nagano, Honshū, Japan