In ancient times, Lake Hamana was a freshwater lake separated from the ocean. However, a great earthquake in 1498 altered the topography of the area, resulting in the lake getting connected to the Pacific Ocean and turning the fresh water into salt water, creating an intricate shoreline. Today the lake offers a wide range of water activities, including cruising, water skiing, wind surfing, kayaking, parasailing and fishing.

Kanzanji Onsen is a hot spring resort area on an inlet on the eastern shore of Lake Hamana in Hamamatsu City. The area contains a number of hotels and traditional Japanese inns (ryokan) and is surrounded on three sides by the lake. Boasting stunning natural beauty, most of the lake’s main attractions are concentrated around this area. The resorts offer an attractive range of hot spring baths with the outdoor open-air baths providing magnificent views onto the lake. Some of the many attractions which can be enjoyed here include Kanzanji Temple, Kanzanji Ropeway, Hamamatsu Flower Park and Pal Pal Amusement Park.

Kanzanji Temple is believed to have been founded in 810 by the famous monk, Kobo Daishi. Located in the northern part of Kanzanji Onsen, the expansive grounds of the historic Buddhist temple stretch over the forested tip of a peninsula out into Lake Hamana. It's a fantastic place to enjoy the great outdoors and activities such as hiking through forest paths with breathtaking views of the water.

Kanzanji Ropeway is the only ropeway in Japan that passes over a lake. The ropeway stretches 723 meters (2,372 ft), and offers stunning views of Lake Hamana, the Pacific Ocean and the town below. On a clear day, you can even see Mount Fuji off in the distance. The ropeway briskly takes you up to the summit of Mount Okusa (113 meters [370 ft]) in about 4 minutes. At the top you can enjoy the free observation deck along with the Hamamatsu Music Box Museum.

You can also admire the lake up close and personal by taking a relaxing cruise from the water on a sightseeing boat. The scenery is just as beautiful from the surface of the water as it is from above, with boats traveling out from Kanzanji’s inlet and exploring deep into Lake Hamana. The boats can be boarded at Kanzanji Temple or from the entrance to the Hamamatsu Flower Park.

The must-try dish in Lake Hamana is Japanese eel, which is called unagi in Japanese. Eel has been cultivated here since ancient times with the Hamanako brand known throughout Japan. The locally farmed delicacy is excellent when broiled and served over a bed of fluffy rice in a dish called unadon (when served in a special rectangular box, it's called unaju).