You can find the keys to Mozart’s wine cellar, the Pentagon, Frankenstein’s Castle, and Hitler’s bunker in Estes Park, CO. The Baldpate Inn’s key collection was inspired by the play ‘The Seven Keys to the Baldpate Inn’, which was written in 1913 about the then-fictional hotel. Now, the Inn is home to the world’s largest collection of keys – about 20,000 – from around the world. Source Source 2 Source 3