Rupnica

Rupnica is one of the most interesting geological sites in Croatia: an outcrop of volcanic rock with columnar structure, lying southwest of the village of Voćin in the east of the country. It sits within Papuk Geopark and has held special protected status since 1948.

What is Rupnica?

Rupnica is an outcrop of rhyolite, a light-coloured volcanic rock, showing columnar jointing. The rock has split into regular, elongated columns. Such forms are usually associated with basalt, which is exactly why a rhyolite example attracts geologists. Researchers describe the rock as a porphyritic rhyolite containing albite and aegirine-albite.

How did the columns form?

Columnar jointing appears when a hot mass of rock cools and contracts, and the stress cuts it into regular blocks. Studies suggest that at Rupnica this happened in a shallow, low-pressure setting with fast cooling. The volcanic rocks of the area are linked to the Cretaceous period, although dating results are not unambiguous and the literature offers different estimates. What you see here is a trace of ancient volcanic activity that shaped the landscape of Papuk.

Croatia's first natural monument

Rupnica used to be a quarry. Today no stone is extracted, and the place is protected as natural heritage. On 14 October 1948 it was declared the first natural heritage site of Croatia, specifically a geological monument of nature. That alone is a good reason to stop here, even briefly.

Papuk Geopark

Rupnica belongs to Papuk Geopark, which gained UNESCO recognition in 2007 and is a member of the European and Global Geoparks Networks. It is one of the geosites of the area, alongside other places tied to Cretaceous volcanic rock. Visitors can therefore combine a stop here with exploring the region's other geological sights.

Who is it for?

• people interested in geology and volcanism,
• photographers who enjoy geometric rock forms,
• families and school groups looking for a simple lesson in Earth history,
• travellers exploring Slavonia and the Papuk area.

Frequently asked questions

Where is Rupnica?

In Croatia, southwest of Voćin, within Papuk Geopark.

What makes Rupnica special?

Its columnar-jointed volcanic rock, rhyolite, and the fact that it was the first protected natural monument in the country.

Since when is Rupnica protected?

Since 14 October 1948.

Is it still a quarry?

No. Stone was once extracted here, but today it is protected natural heritage.

Is Rupnica basalt?

No, it is rhyolite. Columnar jointing is more common in basalt, so the site is sometimes mistaken for basalt.

Is Rupnica part of a geopark?

Yes, it is part of Papuk Geopark, a member of the European and Global Geoparks Networks supported by UNESCO.