Sluňáky

Sluňáky is a small but geologically remarkable nature monument located about 3 km southeast of Kadaň, within the municipality of Rokle in the Ústí nad Labem Region of the Czech Republic. The name comes from a local folk term for the large quartzite boulders scattered across the terrain here, which generations of locals have simply called "sluňáky." It's a rewarding stop for anyone curious about geology and the deep history of the Czech landscape, and equally pleasant as a quiet walking destination near Kadaň.

What shapes the landscape at Sluňáky?

The heart of the protected area consists of quartzite boulders and small rock outcrops — the remnants of what was once a continuous silica horizon resting on gneisses of the Ohře crystalline complex. The formation of such a silica layer points to an unusually long period during which the land surface received no sediment cover and the climate stayed warm and dry. Under those conditions, silica-rich solutions rising from the underlying rock precipitated at the surface. The result is a set of exceptionally hard, weathering-resistant blocks that survived intact while the softer surrounding rock eroded away around them.

Why is this site considered so rare?

Sluňáky is regarded as one of the finest surviving examples in the Bohemian Massif of how its surface looked in a practically unchanged state from the beginning of the Mesozoic or Tertiary era right up to the present day. It's precisely this continuity and authenticity of the geological landscape that gives the reserve its scientific value — formations of this kind are uncommon anywhere in the country.

How were these boulders used historically?

Quartzite blocks like these once occurred more widely around Rokle and were quarried for years to produce dinas, a refractory material used in the construction of blast furnaces. As a consequence of that extraction, the boulders still standing at Sluňáky today are among the last remaining occurrences of this type of formation in the Czech Republic, which adds further weight to the site's protected status.

When and why was the site protected?

The location was declared a natural monument (přírodní památka) by the regional authority in Chomutov on 24 August 1966. The protected area covers 3.54 hectares. The purpose of the designation is to preserve this unique geological relic and the last surviving quartzite boulders of this type in the country from further degradation or extraction.

Where exactly is Sluňáky located?

The reserve lies in the Chomutov district of the Ústí nad Labem Region, within the municipality of Rokle, roughly 3 km southeast of the town of Kadaň. It's a small, quiet corner of the Krušné hory (Ore Mountains) foothills, most easily reached on foot or by bike from the surrounding villages.

Frequently asked questions

What does "sluňáky" mean? It's a local folk name for the large quartzite boulders and rock outcrops scattered across the terrain near Rokle.

Since when has the area been protected? Since 24 August 1966, when it was designated a natural monument by the regional authority in Chomutov.

How large is the reserve? The protected area covers 3.54 hectares.

What were the boulders historically used for? They were quarried to produce dinas, a refractory material used in blast furnace construction.

Where exactly is the site located? About 3 km southeast of Kadaň, within the municipality of Rokle, in the Ústí nad Labem Region.