Gythio is 45 minutes by car from Sparta on the well-graded EO39, and about three and a half hours from Athens through Tripoli and Sparta. KTEL Lakonias runs a few daily buses from Athens via Sparta, the last leg taking about an hour.
Gythio is also the main eastern gateway to Mesa Mani (the inner peninsula) and the Diros Caves: about an hour south by car along the coast road. In summer the small port operates a weekly ferry to Kythira and Crete (Antikalamos), run by LANE Lines — schedules change yearly so check at the port the day before.