Coordinates: 36°57′50″N 21°39′35″E / 36.9640°N 21.6596°E Voidokilia Beach (Greek: Παραλία Βοϊδοκοιλιά, pronounced [voʝðociˈʎa]) is a popular beach in Messinia in the Mediterranean area. In the shape of the Greek letter omega (Ω), its sand forms a semicircular strip of dunes. On the land-facing side of the strip of dunes is Gialova Lagoon, an important bird habitat. The beach has been named "A Place of Particular Natural Beauty". It is part of a Natura 2000 protected area.
Above the beach is Nestor's Cave and above this are the ruins of thirteenth-century Frankish castle (Old Navarino or Palaiokastro). Overlooking the beach at the north eastern end is the tomb of Nestor's son, Thrasymedes of the Mycenaean period (1680–1060 BC) with Neolithic finds at the same site showing occupation as early as 4000 BC.
The beach is presumed to be Homer's "sandy Pylos" where Telemachus was welcomed by King Nestor when searching for his father, Odysseus. According to myth, Nestor's Cave is where Hermes hid the cattle stolen from Apollo.
A hiking route begins from Voidokoilia. The climb towards Nestor's Cave begins at the south-west end of the beach, while after the cave the route continues towards Paliokastro. Voidokilia is next to Petrohori in Messinia, Greece. Though the ruins are not fenced off, the castle ruins are sign-posted as closed and tourists walk through the castle or around the walls at their own risk.