Lake Hańcza

Lake Hańcza (roughly "HAHN-chah") is the deepest lake in Poland, plunging to about 108.5 m, set among glacial hills in Suwałki Landscape Park in the far northeast of the country, about 20 km northwest of Suwałki. With crystal-clear water, boulder-strewn shores and steep spruce-covered slopes, it feels more like a mountain lake than a typical lowland one. It is worth visiting for the views, walks and a bracing swim – and, for certified divers, it is one of Poland's most famous dive sites.

How deep is Lake Hańcza?

The most commonly quoted maximum depth is 108.5 m, though different surveys give anything from about 105.5 to 113 m. That makes Hańcza the deepest lake not only in Poland but in the whole central part of the European Lowland. Its average depth of 38.7 m is remarkable for a lake of only about 311 hectares. It is a long, narrow glacial trough lake – about 4.5 km long and up to 1.15 km wide – lying at around 227 m above sea level. The Czarna Hańcza River flows through it.

Nature and protection

The water is rated top-class for purity, with visibility of around 6 m. Cold-water fish such as burbot and bullheads live here, along with a native whitefish. The name comes from the extinct language of the Yotvingians, a Baltic people who once lived in this region. The whole lake is a nature reserve inside Suwałki Landscape Park and was added to UNESCO's Project Aqua list in 1974. The regional environmental authority is working on enlarging the reserve and a new management plan, so follow the signs on site.

Things to do at Lake Hańcza

• Swimming – the main beaches are at Błaskowizna (with a pier) and Stara Hańcza. The water stays cool even in summer.
• Viewpoints – the steep eastern shore and the hills near Leszczynowa Góra and Mierkinie give the best panoramas.
• Scuba diving – depth and clarity draw divers year-round, including under the ice in winter. It is demanding: there have been fatal accidents, so dive only with proper certification and a buddy.
• Hiking and cycling – trails of Suwałki Landscape Park run around the lake; the Bachanowo boulder field reserve lies on the Czarna Hańcza nearby.

Allow an hour for a scenic stop, or half a day with a swim and a walk.

Practical information (as of October 2026)

• Admission: free; accessible year-round under reserve rules.
• Best time: July and August for swimming; fall and winter for quiet walks and photos. In cold winters the lake freezes.
• Getting there: Suwałki is about 300 km northeast of Warsaw via the S8 and S61 expressways, with trains from Warsaw and Białystok. From Suwałki, drive local roads toward Jeleniewo and Wiżajny to Błaskowizna or Stara Hańcza; public transport is limited, so a car or bike is best. Signs are in Polish.
• Information: Suwałki Landscape Park office and tourist information point in Malesowizna-Turtul.

Nearby

• Suwałki Landscape Park: the Turtul viewpoint and Bachanowo boulder field,
• Suwałki and its District Museum,
• Wigry Monastery and Wigry National Park,
• the tripoint of Poland, Lithuania and Russia near Bolcie.