Sloup Castle, also known as Perkenstein or Pirkštejn in Czech and Einsiedlerstein or Bürgstein in German, is a unique rock castle located in the municipality of Sloup v Čechách in the Liberec Region of the Czech Republic. The castle was built in the 14th century on a steep rocky outcrop, and it served as a fortified defensive structure to protect the surrounding lands from invaders.

The castle consists of a main tower, several buildings, and fortifications built into the natural rock formations of the area. The castle was extensively renovated in the 16th century, and it was also used as a hideout for robbers during the Middle Ages. Today, the castle is a popular tourist attraction, and visitors can explore the castle's fascinating history and stunning architecture.

The castle is surrounded by lush green forests and offers breathtaking views of the surrounding countryside. Visitors can explore the castle's many rooms and passages, including the Knight's Hall, the Chapel of St. Anne, and the castle dungeon. The castle also features a well-preserved drawbridge, which was used to protect the castle's entrance from attackers.

Overall, Sloup Castle is a fascinating and unique historical site that offers visitors a glimpse into the rich history and culture of the Czech Republic.