Lake Ashinoko (°mÎ, Ashinoko) was formed in the caldera of Mount Hakone after the volcano's last eruption 3000 years ago. Today, the lake with Mount Fuji in the background is the symbol of Hakone. The lake's shores are mostly undeveloped except for small towns in the east and north and a couple of lakeside resort hotels.
The best views of the lake in combination with Mount Fuji can be enjoyed from Moto-Hakone (a few steps south from the sightseeing boat pier), from the Hakone Detached Palace Garden and from the sightseeing boats cruising the lake.
Note however, that clouds and poor visibility often block the view of Mount Fuji, and you have to consider yourself lucky if you get a clear view of the mountain. Visibility tends to be better during the colder seasons of the year than in summer, and in the early morning and late afternoon hours.
Two companies, Hakone Sightseeing Boats and Izuhakone Sightseeing Boats, operate boats between Moto-Hakone and Hakone-machi at the lake's southern shores and Togendai and Kojiri at the lake's northern end. A boat cruise from one end of the lake to the other takes roughly 30 minutes and costs 1000 yen. The Hakone Free Pass is valid on the pirate ship shaped Hakone Sightseeing Boats but not on boats operated by Izuhakone.
From Odawara and Hakone-Yumoto
Frequent buses connect Odawara via Hakone-Yumoto with Moto-Hakone and Hakone-machi at the southern end of Lake Ashinoko. The one way journey from Odawara takes about 50 minutes and costs 1180 yen. From Hakone-Yumoto it takes about 35 minutes and costs 960 yen. The Hakone Free Pass is valid on Hakone Tozan buses (bus line H) but not on Izuhakone buses (bus line Z).
There is also a frequently served Hakone Tozan Bus line from Odawara via Hakone-Yumoto to Togendai at the northern end of Lake Ashinoko (bus line T). The one way journey from Odawara takes about 50 minutes, costs 1230 yen and is covered by the Hakone Free Pass. From Hakone-Yumoto it takes about 35 minutes and costs 1050 yen.
A slow and scenic way of approaching Lake Ashinoko from Odawara or Hakone-Yumoto is taking the Hakone Tozan Railway to Gora, followed by a cablecar and ropeway ride to Togendai at the northern end of of the lake. From Togendai one can continue by sightseeing boat to Moto-Hakone or Hakone-machi. The whole journey is covered by the Hakone Free Pass.
There are infrequent buses from Yugawara Station to Hakone-machi and Moto-Hakone (operated by Hakone Tozan and Izuhakone). The one way journey from Yugawara to Moto-Hakone takes 45-60 minutes and costs 1390 yen. The Hakone Free Pass is valid on Hakone Tozan buses but not on Izuhakone buses.
There are buses (operated by Izuhakone Bus) from Atami Station to Hakone-machi every hour. The one way journey takes about 60 minutes and costs 1150 yen. The Hakone Free Pass is not valid on Izuhakone buses.
There are buses from Mishima Station to Hakone-machi and Moto-Hakone (bus line N, operated by Numazu Tozan Tokai Bus) every hour. The one way journey from Mishima to Moto-Hakone takes about 50 minutes and costs 1030 yen. The Hakone Free Pass is valid on these buses.
There are two buses per hour between Gotemba Station and the northern and eastern shores of Lake Ashinoko (bus lines V and W, operated by Odakyu Hakone Highway Bus). The one way journey from Gotemba to Togendai takes about 30 minutes and costs 1020 yen. The Hakone Free Pass is valid on these buses.