Eisenhart Bridge and Pavilion, Wörlitzer Park

The Eisenhart is actually a building made of lawn iron stone (an iron ore known since the Iron Age), but at the same time it bridges the canal that separates Neumark's garden. A mobile utility bridge also leads over this canal, so that Neumark's garden can also be reached. In addition, the island can be reached by a ford. The South Sea Pavilion and the Library Pavilion (1783/84), which were designed by Friedrich Wilhelm von Erdmannsdorff, stand on the Eisenhart. This houses the otaunity collection (ethnographic objects from the Pacific region) that Johann Reinhold Forster gave to Prince Franz in 1775.

The Eisenhart is actually a building made of bog ironstone (an iron ore known since the Iron Age), but at the same time it bridges the canal that separates Neumark's garden. A mobile service bridge also leads over this canal to reach Neumark's garden. The South Sea Pavilion and the Library Pavilion (1783/84), designed by Friedrich Wilhelm von Erdmannsdorff, are located on the Eisenhart. The latter houses the Otaheite collection (ethnographic objects from the Pacific region) that Johann Reinhold Forster gave to Prince Franz in 1775.
Source: de.wikipedia.org

The rock looked like cooled lava. Interesting.