What was the main port of ancient Sparta?

Gytheion was the main port of ancient Sparta.

The harbor stood on the Laconian Gulf, roughly 40 kilometers south of Sparta in the Eurotas valley. Although Sparta was inland, Gytheion gave the Spartan state access to maritime trade, naval operations, and movement along the southern Peloponnese.

Ancient sources also connect Gytheion with Spartan naval activity during the Peloponnesian War. The settlement was strategically valuable because ships could reach the Aegean and other Greek coasts from the Laconian Gulf.

Gytheion later remained important under Roman rule. Modern references commonly spell the ancient town Gythium or Gytheion, while the present-day Greek town is usually called Gytheio.