The ruins of the medieval castle, reminiscent of the devil's horns, have become one of the symbols of Bohemian Paradise and a subject for many poets, writers and photographers.

The castle was built for defensive purposes. Its location on two steep basalt rocks and a system of several walls made Trosky an almost impregnable castle. On the tops of both rocks stood defensive but also residential towers. On the higher and more slender peak called Panna, the tower had 3 floors and served as a castle chapel. The lower peak, called Baba, was a two-storey building. Between the two rocks stood a residential palace.

The defences further consisted of an elaborate system of triple belt walls connected by gates. Behind the first gate was a guardhouse and smaller outbuildings. Behind the second gate were stables and smaller residential buildings. On the lower floors of the palaces behind the third gate were large warehouses for supplies needed during the siege. The water came from the castle's own 30 m deep well and from the rainwater reservoir at Panna.

It is said that under the castle there is a secret cellar and cave with underground water pools, which the castle builder Čeněk of Vartenberk built in case of a siege. This secret cave system has attracted the attention of researchers since the 18th century.

During the tour, the visitor has the opportunity to learn about the history of the castle and climb the Babu Tower and the lookout under the Panna Tower. Both places provide a unique view of the surrounding landscape.