Stoa Basileios, meaning Royal Stoa, was a Doric stoa in the northwestern corner of the Athenian Agora, which was built in the 6th century BC, substantially altered in the 5th century BC, and then carefully preserved until the mid-second century AD. It is among the smallest known Greek stoas, but had great symbolic significance as the seat of the Athenian King Archon, repository of Athens' laws, and site of "the stone" on which incoming magistrates swore their oath of office. Wikipedia