Lake Hamanako in Shizuoka Prefecture is Japan’s tenth largest lake. The lake is a commercial source of cultivated Japanese eel, nori, oysters, and Chinese soft-shelled turtles. Fishers catch sea bass whiting, and flounder here, among other species. This is not a multi-day destination, but rather a place to make a stop on the way from the Tokyo or Shizuoka area to the Kyoto/Osaka Kansai area.
The lake has been developed as a resort area, with an amusement park and onsen with lake views. Some of the onsen resorts accept day visitors, such as Hanasaki no Yu. Amusement park Pal Pal is especially interesting for families with kids between 6-12 years old. You also can take a short cruise on a sightseeing boat allowing you to enjoy the scenery from the surface of the lake. Another way to enjoy the view is from the air aboard the Kanzanji Ropeway that connects Lake Hamanako with the lookout area at the peak of Mt. Okusa, 113 meters above sea level. The Hamamatsu Flower Park has something in bloom every season, but the best seasons are spring, summer, and autumn.
Of course, a visit to Lake Hamanako is not complete without tasting the local specialty, of which unagi (eel) that is locally farmed is especially recommended. You can find this dish in most restaurants in the area.