One of the places Fayette and I visited was the Baldpate Inn. The inn was built in the early 1900's and was named after a mystery book Seven Keys to Baldpate by Earl Derr Biggers (I did not get a good picture of the inn). The storyline had seven visitors going to an inn thinking they had the only key. In the beginning visitors to this inn were given a key to keep. A metal shortage during WWI put a stop to the custom, so visitors started leaving keys at the inn. There are keys to Mozart's wine cellar, Sherwood Forest, Hitler's desk, house keys, car keys, encryption keys, typewriter keys, monkeys, keys to the city, piano keys, hotel keys, key cards. They are everywhere, in display cases, hanging from the rafters and are tagged with where they came from and the date.
You can look and look and see something different every time you go.