Marienglashöhle cave

The Marienglashöhle is a show cave situated in the Thuringian Forest. While it features natural caverns, it primarily consists of cavities resulting from historical gypsum and copper mining activities. It is thus managed and presented as both a cave and a show mine. This geological site is designated as a geological natural monument. Positioned between the towns of Friedrichroda and Bad Tabarz, the Marienglashöhle is easily accessible. Visitors can find a large parking lot along Federal Highway 88, and there is also a Thuringian Forest Railway named after the cave nearby. Guided tours are available to explore the cave, attracting approximately 71,000 visitors annually.

In 1775, construction of the entrance adit began with the intention of mining copper. Although no copper shale was found, a gypsum deposit was discovered in 1778. Gypsum mining continued underground until 1903. In 1784, one of Europe's largest and most beautiful gypsum crystal druses was discovered within the cave. With a diameter of approximately ten meters, this druse was almost entirely lined with colorless and transparent gypsum crystals known as Marienglas.