The Geologisches Freilichtmuseum (Geological Open-Air Museum) is a 200-metre circular path, showcasing more than 50 information boards and 16 different types of rock, including 30.000-year-old travertine and 1.4 billion-year-old Indian granite. The site also includes examples of historic quarrying equipment.

The ‘museum’ is located near the Romberg Quarry (PiP 4 and 5) ; the only Bentheim sandstone quarry, which is still in operation. (Although officially not open for visitors a local inhabitant told me there was no problem to have a quick look.)