In the north of modern Sparta stands a massive limestone building, about 12.5 by 8.3 metres, known as the Leonidaion or 'Tomb of Leonidas'. It was excavated in 1892, dates to the late 5th century BC and is the only monument of the ancient agora still standing.
No one knows for sure what it was. Some think it was a memorial (cenotaph), others a temple of Apollo Karneios. The link with Leonidas comes from tradition: the ancient traveller Pausanias wrote that the king's remains were brought back to Sparta and that games were held every year in his honour.