Lake Hakone, c. 1920, as it was colloquially named by resident foreign expatriates. The proper Japanese name for the body of water is Ashi-no-ko [lake of reeds].
See also:
Hakone Hotel, c. 1910-1950
Mount Fuji reflected upon Lake Ashi, c. 1920
Matsuzaka Hotel, Ashinoyu, c. 1910
“Hakone Lake (2378 ft.) known also as Ashi-ko, a clear sheet of water 3 1/2 M. long, 1/2 M. wide, and about 150ft. deep, is circled by half-bare volcanic mts. of which the tallest is Komo-ga-take (Pony Peak, 4452 ft.) at the E.
“The lake is near the border line of Suruga Province, and is drained chiefly by the Hayagawa, which flows out of its N. end, and after a roundabout course goes through Miyanoshita and falls into Odawara Bay. The distance along the E. shore to Umijiri, the hamlet at the topmost point, is 5 M.; thence to Nagao-toge [Nagao Pass] about 3 M.”
– Terry’s Japanese Empire, T. Philip Terry, 1914
Mt. Fuji from Lake Ashi, Hakone, c. 1930.
Map: Hakone and Lake Ashi (Lake Hakone) (Japan: The Official Guide, 1941) Click to enlarge.