Lake Krasowe in Kusięta

Just northwest of Olsztyn near Częstochowa, in the village of Kusięta between the Zielona Góra reserve and the Towarne Hills, lies Lake Krasowe — one of Poland's rarest natural phenomena. The pond formed in a karst sinkhole, a collapse of the ground over underground voids in limestone. The phenomenon is so rare that outside the Kraków-Częstochowa Upland, karst lakes in Poland occur only on the Lublin Upland.

Water that should vanish

Normally water in karst terrain disappears into underground cave systems. In Kusięta it was saved by impermeable clays that accumulated at the bottom of the sinkhole and sealed the lake basin. Nearby you can also see a uwał — a larger depression made of several sinkholes, which fills with water after downpours, only for the water to quickly vanish into the underground world of the Jura. A short walk between the two basins is the best demonstration of how karst works.

Geological trail and hiking routes

The geological educational trail “In the Land of White Rocks” runs through Kusięta, leading to the lake and up the limestone hills. The red Trail of the Eagles' Nests and the orange Trans-Jura Horse Trail pass nearby, so the pond fits naturally into a longer Jura trip.

Practical information

The easiest access is through Kusięta, just past the railway crossing; a small picnic spot sits by the pond. It makes a great short cycling trip from Olsztyn (the castle in Olsztyn is 3.5 km away). Come in spring or after heavy rain — the uwał may then be full of water and the whole phenomenon explains itself.