The Castelchiaro ruin is situated on Monte di Mezzo above Campi al Lago in the municipality of Vadena. Kalterer See lake is at your feet.

The precise date of the construction of Castelchiaro is not known. It is likely that it was built between 1200 and 1250 by the Counts of Rottenburg. The South Tyrolean Castle Institute estimates that construction started even before 1200.

The castle was protected from attacks by an impressive shield wall. The main castle consisted of an oval high wall and some residential buildings inside them. There were two outer baileys. After 1610 Castelchiaro was no longer inhabited and fell into decay. The remaining walls of the ruin were not preserved until the 20th century. Inside there are well preserved remnants of the old palace with frescoes dating back to the 15th century. The walls of the ruin were fixed therefore it can be visited from the out side.