The Felsenreitschule (Summer Riding School) in Salzburg was built at the site where the conglomerate for the construction of the Cathedral was cut from the rock during the first half of the 17th century. The Felsenreitschule was carved into the Mönchsberg cliff in 1693 under Archbishop Johann Ernst Thun after plans by the baroque architect, Johann Bernhard Fischer von Erlach. (Source: salzburg.info)