Dragon's Lair at Mixnitz, Natural cave system in Pernegg an der Mur, Austria

Drachenhöhle bei Mixnitz is a 542-metre-long cave in the Röthelstein south of Bruck an der Mur, with an entrance 20 metres wide and 12 metres high at 950 metres above sea level. Inside, the main passage reaches heights of 10 to 15 metres and widths up to 40 metres, and a masonry cable-car foundation stands beside the portal.

Between 1918 and 1923, workers extracted roughly 2,500 tons of phosphoric acid from the cave's sediments to address fertilizer shortages after World War I. This mining operation was an important economic activity for the region during that period.

Medieval finders took the cave bear bones for dragon remains, giving rise to the saga of the Mixnitz dragon slayer. The cave was long known locally as Kogellucken, and its 15-metre-high portal made it visible from afar. A coat of arms stone inside recalls the 1387 expedition of Pfarrer Otto von Bruck, who reached the great dome 500 metres in.

The cave lies at 950 m above sea level in the Röthelstein above Mixnitz, southeast of Bruck an der Mur. The 20 m wide and 12 to 15 m high portal is visible from afar; inside, the main passage runs 542 m to the large dome that Pastor Otto of Bruck reached in 1387. A walled cable-car foundation beside the entrance is a remnant of the 1918–1923 guano mining. The site has been a natural monument since 1949.

Scientists found over 30,000 cave bear bones and Stone Age tools here from around 65,000 years ago. These discoveries show that people have been familiar with this area for an extremely long time.