Prášilské jezero

Prášilské jezero is the smallest of the glacial lakes scattered across the Šumava mountains, tucked into the forest on the eastern slope of Mount Poledník in the municipality of Prášily, Plzeň Region. Sitting at roughly 1,080 metres above sea level and covering barely 4 hectares, it is far more modest in scale than its better-known neighbours, but that very smallness, combined with the dense surrounding woodland, gives it a quiet, almost secretive character that larger Šumava lakes lack.

How did the lake form?

Like the other Šumava lakes, Prášilské jezero owes its existence to the retreat of a glacier at the end of the last ice age. As the ice mass on the flank of Poledník melted and withdrew, it pushed ahead of it a mass of stone and gravel that piled up into a moraine ridge. That ridge still acts today as a natural dam, holding back the meltwater that filled the glacial basin (a cirque, or "kar" in Czech) carved out by the ice.

How large and how deep is it?

The lake measures about 280 metres in length and 180 metres in width. Depth figures vary slightly between sources, but the lake reaches a maximum of roughly 15 to 17 metres, with an average depth of around 8 metres — a considerable depth for a Šumava lake of this size. The water carries the characteristic dark tint typical of forest-bound glacial lakes with a high content of organic matter washed in from the surrounding peat and woodland.

What should visitors know before going?

The lake lies within the strict nature reserve zone of Šumava National Park, so direct access to the shoreline and swimming are both prohibited. Visitors can only view the lake from designated observation points and walkways built along the trail, keeping the immediate shore undisturbed. The surrounding slopes are covered in old-growth spruce and beech forest, and the near-total silence of the area gives the impression of a place cut off from the outside world.

What history is tied to this place?

On the moraine ridge close to the water stands a modest stone memorial to a student named O. Kareis, who drowned in the lake in 1927. It is a quiet reminder that, however picturesque the lake looks, its waters can be treacherous — and that the swimming ban is not merely a bureaucratic formality.

How do you get there?

Most visitors set out from the village of Prášily, from where a marked forest trail leads to the lake. The route is not especially demanding, but it does cross uneven forest terrain, so sturdy footwear and enough time are worth planning for, particularly if the walk is combined with visiting other nearby Šumava sights.

Frequently asked questions

Can you swim in Prášilské jezero? No. The lake sits within the strict protection zone of the national park, and both swimming and entering the water are forbidden.

How deep is the lake? Sources give a maximum depth of around 15 to 17 metres, with an average depth of about 8 metres.

How did the lake come to exist? It formed when a glacier melted at the end of the last ice age, leaving behind a moraine ridge that dams the meltwater in place.

Is the lake easy to reach? Yes, a marked hiking trail leads there from the nearby village of Prášily, though the immediate shoreline itself is off-limits to protect the surrounding nature.