The 20 Largest Lakes in Japan

Japan has hundreds of lakes, but few really stand out for size, depth, or influence on people’s lives. Understanding which are the largest lakes in Japan is useful for those interested in tourism, natural resources, history, and regional development.

In this article, you will find the 20 largest lakes in Japan, with official data on area, depth, name in kanji, and practical or historical information for those interested in geography, travel, economy, or Japanese nature.

How many lakes are there in Japan?

According to the Ministry of the Environment of Japan, the country has about 6,222 lakes with more than 1 hectare of area. Most are small mountain lakes, but about 20 have national prominence for area, depth, historical or ecological importance. This abundance is a result of volcanic geography, humid climate, and the numerous natural depressions that have retained water for millennia.

Among these, lakes like Biwa, Kasumigaura, and Saroma are true landmarks. Many lakes are essential sources of drinking water, irrigation, fishing, tourism, and flood protection. Others, like the lakes of Mount Fuji, are world-famous for their landscapes and their connection to Japanese culture.

The Five Lakes of Mount Fuji (富士五湖)

Located in Yamanashi Prefecture, the Five Lakes of Mount Fuji — Yamanakako (山中湖), Kawaguchiko (河口湖), Saiko (西湖), Shojiko (精進湖), and Motosuko (本栖湖) — were formed by ancient volcanic eruptions of Fuji itself. They offer some of the most classic and photographed views of Japan, especially in the months when the top of Fuji is covered in snow.

This region is one of the most visited tourist hubs in the country. In addition to natural landscapes, it offers camping, hiking, water sports, resorts, onsen, and, of course, cycling and cherry blossom viewing routes in early spring. Each lake has its own profile and audience, but all ensure excellent infrastructure for those seeking direct contact with Fuji.

1. Lake Biwa (琵琶湖)

The Lake Biwa (琵琶湖) is the largest and oldest in Japan, with an area of 670.3 km² and a maximum depth of 104 meters. Located in Shiga, it supplies about 15 million people, including major cities like Kyoto and Osaka. Its biodiversity is impressive, with over 1,000 aquatic species, including 46 endemic fish.

The surrounding area of the lake is densely populated and offers tourist infrastructure, trails, bike paths, and museums. Biwa has been a Ramsar Site since 1993 and is a recurring theme in Japanese poems and art. Archaeologists find traces of human settlements along its shores dating back up to 10,000 years.

2. Lake Kasumigaura (霞ヶ浦)

The Kasumigaura (霞ヶ浦), in Ibaraki, is the second largest lake in the country, with 167.6 km² and only 7 meters of maximum depth. It is vital for rice irrigation, shellfish and shrimp fishing, and supplying nearby cities.

Despite its beauty, it faces eutrophication due to agricultural activity around it, with ongoing environmental recovery programs since the 1980s. The lake is surrounded by one of the most extensive cycling routes in Japan, very popular among athletes.

3. Lake Saroma (サロマ湖)

The Saroma-ko (サロマ湖) is in Hokkaido, with 151.9 km² and a maximum depth of 19.6 meters. It is a brackish coastal lake connected to the Sea of Okhotsk, making it famous for oyster and scallop production.

During winter, part of the lake freezes and is used for ice fishing. The region is less touristy but attracts visitors seeking untouched nature, small fishing villages, and authentic Hokkaido experiences.

4. Lake Inawashiro (猪苗代湖)

The Inawashiro-ko (猪苗代湖), in Fukushima, has an area of 103.3 km² and reaches a depth of 94.6 meters. Its water is known for its blue color and purity, which is why it is called “mirror of the sky.”

In addition to supplying water, the lake attracts many tourists for water sports and hiking. It is also a stopover for thousands of migratory swans in winter, becoming a birdwatching spot.

5. Lake Nakaumi (中海)

The Nakaumi (中海) is located between Shimane and Tottori, with 86.2 km² and a maximum depth of 17.1 m. Its brackish waters result from its connection to the Sea of Japan, creating an ecosystem rich in eels, shellfish, and waterfowl.

The lake is crossed by modern bridges, connecting cities like Matsue and Sakaiminato. The islands of Daikon and Eshima, within Nakaumi, are points of historical interest, with shrines and archaeological remains.

6. Lake Kussharo (屈斜路湖)

The Kussharo-ko (屈斜路湖), in Hokkaido, has 79.3 km² and a maximum depth of 117.5 meters. It is a caldera lake, surrounded by mountains, with natural hot springs by the water’s edge.

In winter, hundreds of swans seek refuge on the warm shores. Kussharo is ideal for those looking for outdoor hot springs and underexplored nature tourism.

7. Lake Shinji (宍道湖)

The Shinji-ko (宍道湖), in Shimane, covers 79.1 km² and has only 6 meters of maximum depth. Its slightly brackish waters favor the fishing of shrimp, eels, and shellfish, the basis of the local cuisine.

The lake is famous for its sunsets and hosts seasonal festivals that celebrate riverside culture. Its shoreline features parks and recreational areas used by residents and tourists.

8. Lake Shikotsu (支笏湖)

The Shikotsu-ko (支笏湖), in Hokkaido, is a volcanic lake with crystal clear waters, covering 78.4 km² and an impressive depth of 363 meters. It is known for its transparency: visibility can exceed 20 meters.

The site is part of a national park, hosts winter festivals, and is popular for diving, kayaking, and hiking. Despite the harsh winter, the lake rarely freezes due to its depth.

9. Lake Tōya (洞爺湖)

The Tōya-ko (洞爺湖), in Hokkaido, has 70.7 km² and up to 179.9 meters of depth. Formed in a volcanic caldera, it has a central island (Nakajima) and is surrounded by geothermal areas and hot spring resorts.

It is a destination for hiking and boat tours, famous for its annual fireworks festival throughout the summer. Tōya hosted the G8 summit in 2008.

10. Lake Hamana (浜名湖)

The Hamana-ko (浜名湖), in Shizuoka, has 65 km² and a maximum depth of 13.1 m. Its waters became brackish after an earthquake in the 15th century, connecting it to the Pacific.

The lake is a reference for eel and shellfish production, the basis of the local economy. It is very popular for water sports, fishing, beaches, and urban leisure.

11. Lake Ogawara (小川原湖)

The Ogawara-ko (小川原湖), in Aomori, covers 63.2 km², with a maximum depth of 25 meters. Its waters are used for irrigation, supply, and fishing for sea bass, mullet, and shrimp.

There are ecological trails and birdwatching, as well as proximity to air bases that monitor the environmental quality of the lake.

12. Lake Towada (十和田湖)

The Towada-ko (十和田湖) is located between Aomori and Akita, with 61.1 km² and an impressive depth of 327 meters. It is a caldera lake, surrounded by steep slopes and forests that change color with each season.

Boat tours depart from the village of Yasumiya, and the autumn landscape attracts tourists from all over Japan. It is also the setting for legends, such as that of the princess turned into a dragon.

13. Lake Notoro (能取湖)

The Notoro-ko (能取湖), in Hokkaido, covers 58 km² and has a maximum depth of 7 meters. The highlight is the shores that turn red at the end of summer due to the “glasswort” vegetation.

It is an area for shellfish fishing and a resting place for migratory birds, with small communities of fishermen living off the sustainable collection of seafood.

14. Lake Tazawa (田沢湖)

The Tazawa-ko (田沢湖), in Akita, is the deepest lake in Japan, with 423.4 meters, despite its relatively small area (25.9 km²). Its cold, clear waters are home to trout and salmon.

On the shores, there are trails, diving spots, and the famous golden statue of Princess Tatsuko, a symbol of a local legend about eternal youth.

15. Lake Suwa (諏訪湖)

The Suwa-ko (諏訪湖), in Nagano, covers 13.3 km² and reaches a maximum depth of 7.2 meters. The lake is famous for the Omiwatari phenomenon, when the ice cracks forming lines, considered a sign of divine passage.

During summer, it is a stage for water sports and festivals. In winter, ice skating and ice fishing boost local tourism. The surrounding city is also famous for its hot springs.

16. Lake Yamanaka (山中湖)

The Yamanaka-ko (山中湖), in Yamanashi, is the largest of the Five Lakes of Fuji, with 6.6 km². Its shallow waters and open shores favor fishing, windsurfing, canoeing, and cycling tourism.

The view of Mount Fuji is a special attraction. During summer, fireworks festivals take place, and in winter there are ice skating and waterfowl watching activities.

17. Lake Kawaguchi (河口湖)

The Kawaguchi-ko (河口湖), in Yamanashi, has 5.7 km² and a maximum depth of 14.6 meters. It is known for its privileged view of Mount Fuji and its tourist infrastructure, with hotels, cafés, and museums around.

Boat tours are common, and the region is a starting point for trails leading to Fuji. In autumn, the red leaves make the scenery even more sought after.

18. Lake Motosu (本栖湖)

The Motosu-ko (本栖湖), also in Yamanashi, has 4.7 km² and a maximum depth of 121.6 meters. Its blue-green water is a highlight, and the landscape of Mount Fuji reflected in the lake is illustrated on the 1,000 yen note.

It is the deepest lake in the Fuji group, ideal for diving, camping, and water sports, and one of the most preserved in the region.

19. Lake Sai (西湖)

The Sai-ko (西湖), in Yamanashi, covers 2.1 km², with a maximum depth of 71.1 meters. It is the quietest of the Fuji lakes, with the least tourist flow.

Sport fishing and camping are common. The forests around offer great hiking trails, especially in autumn.

20. Lake Shoji (精進湖)

The Shoji-ko (精進湖), also in Yamanashi, is the smallest of the Five Lakes of Fuji, with an area of 0.5 km² and a maximum depth of 15.2 meters. Despite its small size, it is famous for being one of the best spots to photograph Mount Fuji reflected in the water.

The lake is surrounded by small family inns and picnic areas, offering a sense of isolation and tranquility for those seeking direct contact with nature.