Vlčí jámy

Vlčí jámy (Wolf Pits) is a natural monument in the Ore Mountains (Krušné hory), situated on the southwestern slope of Blatenský vrch, northeast of the town of Horní Blatná. Administratively the site belongs to the municipality of Potůčky, although geographically it lies much closer to Horní Blatná. The monument protects two striking features: Vlčí jáma itself and Ledová jáma (Ice Pit), both remnants of medieval tin ore mining.

What exactly are Vlčí jámy?

Vlčí jáma is an elongated collapse pit stretching over 120 meters in length, about 14–15 meters wide, and reaching depths of up to 25 meters. It formed when underground workings of a former tin mine — known as the Wolfgang mine — caved in. Ledová jáma is a much narrower but still deep chasm, ranging from 15 to 20 meters down, likewise created by mining activity dating back to the 16th century. Both pits are visible fragments of a broader system of sinkholes and exposed mining tunnels once used to extract tin ore.

Why doesn't the ice in Ledová jáma melt in summer?

The name "Ice Pit" is no coincidence. Because air circulation inside the narrow, deep chasm is severely limited, a distinctive microclimate forms at the bottom, allowing accumulated snow and ice to persist even through the height of summer. This rare phenomenon draws both curious visitors and researchers studying cave microclimates.

What natural values does the site protect?

The natural monument was declared in 1975 specifically to safeguard three things: the medieval tin-mining workings, the presence of perennial cave ice, and rare, critically endangered species of mosses and animals. The area is notable for its rich fern diversity, including species such as Blechnum spicant, Phegopteris connectilis, and Asplenium septentrionale. Vlčí jámy is also the only known site in the Czech Republic where the rare moss Mielichhoferia mielichhoferiana grows — a species tied to substrates with exposed copper ore veins.

Does the site have historical significance?

Yes — Vlčí jámy stands as direct physical evidence of tin ore mining carried out in the Ore Mountains region as far back as the 16th century. Since 2019, the site has formed part of the UNESCO World Heritage property known as the Mining Landscape of Abertamy–Boží Dar–Horní Blatná, underscoring its exceptional importance to the history of European mining.

How can visitors reach Vlčí jámy?

A nature trail circuit called Horní Blatná – Vlčí jámy loops around the natural monument, running nearly 5 kilometers and both starting and ending at the town square in Horní Blatná. The route features seven information panels with text in Czech and German, letting visitors explore the mining history and natural features of the area at their own pace.

Frequently asked questions

What is Vlčí jámy? A natural monument protecting two collapse pits — Vlčí jáma and Ledová jáma — formed by medieval tin ore mining in the Ore Mountains.

Why doesn't the ice in Ledová jáma melt during summer? Limited air circulation inside the deep, narrow chasm creates a microclimate that preserves snow and ice year-round.

Since when has the area been protected? The natural monument was established in 1975, and since 2019 it has been part of the UNESCO Mining Landscape of Abertamy–Boží Dar–Horní Blatná.

How can you visit Vlčí jámy? On foot, via the roughly 5-km Horní Blatná – Vlčí jámy nature trail that begins and ends at the square in Horní Blatná.