The cathedral in the Spanish city of Salamanca was constructed in 1102, and is therefore one of the oldest such constructions in the world. It features magnificent stone carvings on all its walls, but one of them is a bit more special than the others, so to speak. It bears the depiction of what appears to be a fully dressed astronaut in a space suit, complete with details such as the sole of his shoes. Nobody knows how he got there, or what a 20th century astronaut is doing on the walls of a 12th century religious building.