Tsugaru Fujimi Lake

Tsugaru Fujimi Lake (津軽富士見湖) also known as Mawarizeki Ōtameike (廻堰大溜池) is a reservoir that is located almost entirely within the town of Tsuruta in Aomori Prefecture, Japan, though a portion of its southern shore lies within the city of Hirosaki. It was built in 1660 to collect snowmelt in order to irrigate the fields in the surrounding area.

History
The reservoir's construction was ordered by Tsugaru Nobumasa, daimyō of the Hirosaki Domain in 1660 in order to collect water from snowmelt. Upon completion, its 4.2 km retaining wall became the longest embankment dam in Japan, a record it still holds. In 2010, it was selected by the Ministry of Agriculture, Forestry and Fisheries as one of the 100 best reservoirs in Japan.