Prehistoric underworld discovered beneath Olsztyn Castle

The castle built in the 14th century in Olsztyn, near Częstochowa, was one of the biggest buildings of its type located in that area. Photo: PAP/Maciej Kuroń.

An unknown primeval cave and a system of tunnels and crevices were discovered by archaeologists under the Olsztyn Castle in southern Poland, in the Kraków-Częstochowa upland.

The castle built in Olsztyn (near Częstochowa) in the 14th century was one of the biggest buildings of its type located in that area. The ravages of time left its mark and now the picturesque ruins are a popular tourism destination.

The fortress is situated on different altitudes of a large hill. In the area of the lower castle there is a large cave, where the archaeologists are currently conducting excavations. The findings from previous years show that it served not only as a castle pantry, but also, in prehistoric times, as a shelter for Neandertals, whose stone tools were discovered on site.

"We performed a series of endoscopic drillings and soundings and detected the presence of rock voids with specimens of endemic insects at a depth of over 7 metres under the bottom of the cave", said the geologist Andrzej Tyc from the Institute of Earth Sciences of the University of Silesia. It turned out that what researchers had previously believed to be the bottom of the cave was in fact hardened sediments full of huge crevices beneath.

The voids and crevices turned out to be a prehistoric animal graveyard, dating back to the Ice Age and earlier. According to Adrian Marciszak from the Department of Palaeozoology at the University of Wrocław, these crevices may lead to new, yet unknown parts of the lower castle cave.

Mikołaj Urbanowski, the coordinator of the excavation works believes that there are more similar geological constructions in that area. His statement is backed by the new non-invasive test results which revealed the existence of another large void.

“At the moment, we cannot rule out the possibility that it is related to the castle construction though,” he said.

"The castle hill site requires further systematic research and restoration work. We can only guess the gigantic size of the cave system and tunnels under the castle,” Mr Urbanowski concluded.