The first documents testifying to the existence of a castle in Castro date back to the 13th century: a document of 1282 described it as having a strategic importance to protect the kingdom. It is quite sure that the castle was built on the ruins of a former Byzantine building, which protected the fortified Roman village. In 1480 it was destroyed and then rebuilt and strengthened  in 1572 by the Spanish viceroy.
On the north-western part, stand the thick walls of the Bastion of the buttress, with a single central room and fortified battlements. The Torre Cavaliera, the highest and most imposing one, is a three-story tower with three rooms, covered with barrel vault. The Torre Circolare, dating back to the Aragonese period, has three rooms with small windows and merlons with machicolation.
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The Pilgrimage Church of Wies (Wieskirche) is an oval rococo church, designed in the late 1740s by Dominikus Zimmermann. It is located in the foothills of the Alps in the municipality of Steingaden.
The sanctuary of Wies is a pilgrimage church extraordinarily well-preserved in the beautiful setting of an Alpine valley, and is a perfect masterpiece of Rococo art and creative genius, as well as an exceptional testimony to a civilization that has disappeared.
The hamlet of Wies, in 1738, is said to have been the setting of a miracle in which tears were seen on a simple wooden figure of Christ mounted on a column that was no longer venerated by the Premonstratensian monks of the Abbey. A wooden chapel constructed in the fields housed the miraculous statue for some time. However, pilgrims from Germany, Austria, Bohemia, and even Italy became so numerous that the Abbot of the Premonstratensians of Steingaden decided to construct a splendid sanctuary.