Gytheiois a town and a former municipality inLaconia,Peloponnese,Greece. Since the 2011 local government reform it is part of the municipalityEast Mani, of which it is a municipal unit.It was theseaportofSparta, some 40 kilometres (25 miles) north. Gytheio used to be an important port until it was destroyed in 4th century AD, possibly by an earthquake. Today it is the largest and most important town inMani. It is also the seat of the municipality of East Mani.