During the First Peloponnesian War, the Spartans decided to send an expedition to central Greece. They found, nevertheless, that they were prevented from campaigning beyond the Isthmos because all land routes to the north, through the Argolid, Arkadia and Eleia, were closed to them. This paper considers the political and religious reasons why each of these routes was unavailable to the Spartans and the evidence which suggests that they took the alternative of embarking from their ports of Gytheion and Mothone for a sea journey around the west of the Peloponnese.