Which ancient Greek city-state's council was the Gerousia?

Sparta was a prominent city-state in Laconia in ancient Greece. In antiquity, the state was known as Lacedaemon, while Sparta referred to its capital, a group of villages in the valley of the Evrotas River in Laconia, in southeastern Peloponnese. During the 7th BC, it rose to become the most prominent land military power in the Greek world, a status it retained until its defeat at Leuctra in 371 BC.