Lake Ashi is said to be one of the most beautiful lakes in the world. It lies in the caldera of Mount Hakone, formed over 200,000 years ago due to an volcanic eruption. It stretches about 8km long and is surrounded by mountains on all sides. It is an extremely picturesque lake and is known for the view of Mt. Fuji and scenic boat rides.
To reach Lake Ashi, you have to take the Hakone Ropeway to Togendai Station. It is approximately 20 minutes from Sounzan Station and one hour from Hakone-Yumuto Station. You can take alternate bus routes to the other side of the lake but the Ropeway system is most convenient.
There is a boat ride service available which lasts 30 minutes. The boat itself is modelled on a medieval sailing vessel and is a sight to see in itself. Kids love playing on the boat and it's worth the experience for adults too. It costs 750 yen one way and 1400 yen for a return ticket. If you are adventurous and are with a small group, you could rent a mini peddle boat too.
The sightseeing boat ride takes you to several destinations around different sides of the lake. There are many attractions like the Hakone Shrine, Treasure Museum and Palace Garden on the other side of the lake. If you are lucky, you can get a glimpse of Mt. Fuji, but it depends on the cloud cover.
Hakone Shrine is an iconic structure lying in the middle of the lake which you can see half way along your sailing journey. There is also a restaurant nearby that is popular among tourists. The boat stops at Moto-Hakone Port and Hakone Shrine is a few minutes walk from this station. Hence, the sightseeing boat ride is actually designed to tour you around the sightseeing spots around Lake Ashi, not just a way to appreciate the glorious views. Another stop is Hakone Machi, which is near the Kofuku-in Temple and is near several museums.
One downside is the last ride sets sails at 3:30pm so you cannot enjoy the sunset. Otherwise, this ride is definitely recommended if you are visiting Hakone.