The Leonidaion was an ancient structure located in Olympia, Greece, primarily used as a guesthouse for athletes and dignitaries attending the Olympic Games. Built in the 4th century BCE, it was named after the famous Spartan king Leonidas I, known for his leadership at the Battle of Thermopylae. The building featured a series of rooms and communal areas, providing accommodations and facilities for visitors. This significant structure was part of the larger sanctuary dedicated to Zeus, which included the Temple of Zeus and the Olympic Stadium. The Leonidaion exemplified the importance of hospitality in ancient Greek culture, particularly during the prestigious athletic competitions that attracted participants from various city-states.