Lomeček

Lomeček is a flooded former quarry near the village of Starý Klíčov, part of the Mrákov municipality in the Domažlice district of the Plzeň region, at the foothills of the Šumava mountains. The lake that formed here has become one of the region's most distinctive swimming spots — not just for its clear water, but for an underwater observation feature with no real equivalent anywhere else in Europe.

Where is Lomeček located?

The lake lies close to the villages of Starý Klíčov and Nový Klíčov, both part of the Mrákov municipality in the Domažlice district, Plzeň region. The surrounding countryside sits in the foothills of Šumava in western Bohemia, an area known for hiking trails and open-air bathing spots.

How did the lake form?

Lomeček began as an amphibolite quarry — amphibolite being a hard rock once used in construction and road-building. Quarrying stopped in 1988, and the abandoned pit gradually filled with water, creating a scenic lake roughly 200 metres long and up to 48 metres wide. Depth reaches around 10 metres in places, and the water is notably clear, which has made the site a popular summer bathing spot.

What's inside the underwater observation cabin?

Lomeček's main draw is an underwater observation cabin set at a depth of about 8 metres — a feature that has no counterpart elsewhere in Europe. Visitors can walk into the cabin directly from the shore without getting their feet wet, then watch the lake's underwater life through its windows, no diving gear required.

What lives in the lake?

Lomeček is home to pike, catfish and sturgeon, along with freshwater mussels and crayfish. According to the site's managers, under the right conditions small freshwater jellyfish can even appear, adding another unusual detail to the lake's ecosystem.

What else happens around the lake?

Beyond swimming, the area around Lomeček hosts open-air sculpture symposiums and concerts, drawing visitors even outside the bathing season.

When should you visit?

Summer is the best time to visit, when swimming conditions are at their best and the underwater cabin can be enjoyed comfortably. The grassy and sandy shores are well suited to sunbathing, while the quieter off-season makes the area appealing to anyone looking for a calmer spot in the Šumava foothills.

Frequently asked questions

What is Lomeček? It's a flooded former amphibolite quarry near Starý Klíčov and Nový Klíčov, in the Mrákov municipality, turned into a swimming lake after quarrying ended in 1988.

What makes it different from other lakes? An underwater observation cabin at a depth of 8 metres, unique in Europe, that visitors can enter dry-footed straight from the shore to watch the lake's underwater life.

What kind of wildlife lives in the lake? Pike, catfish, sturgeon, mussels and crayfish, with small freshwater jellyfish reportedly appearing under favorable conditions.

How big is the lake? It's about 200 metres long, up to 48 metres wide, and reaches a depth of around 10 metres.