The way to the Castelchiaro ruins starts directly at the Caldaro lake and leads over the at first quite steep way no. 13 directly up to the ruin. The ruin is secured and can be visited from outside. With paths no. 13 and 13A you finish the circular hike on Monte di Mezzo/Mitterberg and return to the starting point at Caldaro Lake via path no. 13. 

Leuchtenburg/Castelchiaro castle is the ruin of a castle that was built in the 13th century above Kalterer See/Lake Caldaro by the Lords of Rottenburg, in the municipality of Pfatten/Vadena. The fortress was well protected thanks to its position and its striking shield wall. After 1610, Leuchtenburg/Castelchiaro castle remained empty and gradually fell into ruin. Today the ruin is freely accessible, and inside the well-preserved remains of the building, the corridor and the frescoes of the fifteenth century are still visible.