Rock castle

A rock castle, known in German as a *Felsenburg*, is a type of medieval fortress built directly around natural rock formations, which are so central to its design that they define the castle's entire layout. Geographically, these castles fall under the category of hill castles. However, unlike typical hill castles that simply use bedrock as a foundation for separate buildings, a rock castle's whole structure is determined by the shape of isolated rock features like towers or crags.

The castle was usually placed on a rock that already offered a strong defensive position with little extra work. In simpler versions, the rock could be climbed using ladders that were pulled up when danger threatened. Wooden and stone buildings were added onto or against the rock. The rock's physical features—its shape and hardness—dictated what could be built and how extensive the fortifications were.

If the rock was easy to carve, such as sandstone, rooms, passages, steps, wells, and cisterns were often cut directly into it. Wooden or stone structures stood on or next to the rock, using it as a foundation or as walls. Today, the wooden parts are usually gone, but their former locations can sometimes be guessed from beam holes and supports still visible in the stone.

Large numbers of rock castles are found in the southern Palatinate (Palatinate Forest), northern Alsace (North Vosges), North Bohemia, and Saxon Switzerland, where massive sandstone formations provided the right conditions. Most rock castles no longer stand. Many were destroyed and later used as stone quarries by locals, leaving only man-made cuts in the rock and a few other traces. Some, like the ruins of Neuwindstein, still have substantial walls. A few were rebuilt in modern times—for example, Berwartstein Castle at the end of the 19th century, and Trifels Castle, which was intended as a "site of national remembrance" during the Nazi era. In both cases, these were not medieval reconstructions but new designs of their time.

Castle researcher Otto Piper used the term "hewn-out castle" for castles with rooms artificially carved from the rock, citing Fleckenstein, Trifels, and Altwindstein as examples. These are closely related to cave castles, which also often feature man-made rock-cut rooms.