The limestone headlands of Paleokastritsa have been sculpted by Ionian currents for millennia, leaving a jagged coastline of sea caves, natural arches, and blue-water grottos accessible only by boat. Byzantine monks chose this bay for its isolation in the thirteenth century, but the cave network beneath the cliffs remained unmapped until fishermen began guiding tourists through the channels in the 1960s. Today the tradition continues from Agios Spiridonas Beach, where a fleet of wooden kaïkis and fibreglass speedboats depart hourly between dawn and dusk. Paleokastritsa boat tours to caves anchor the bay's maritime economy. Operators run tight circuits to a dozen named sites: the Blue Eye cave, whose entrance glows cobalt at midday when sunlight refracts through twenty metres of seawater; the Nausica grotto, named for the Phaeacian princess who legend says met Odysseus on this shore; and the twin arches at Ortholithi, where wave erosion has carved a natural bridge through the headland. Most circuits also call at Paradise Beach and Yali Beach, crescent coves with no road access, where passengers wade ashore for thirty-minute swimming stops. The limestone here is soft enough that each winter storm reshapes the cave mouths, and captains adjust their routes accordingly. The water itself is the attraction. Ionian transparency peaks in early summer, when visibility reaches forty metres and the seabed appears close enough to touch. The caves amplify this effect: inside the larger grottos, reflected light turns the water a luminous turquoise, and the rock walls glow orange where iron oxide streaks the stone. Geologists trace the cave formation to the Pliocene epoch, when tectonic uplift raised the seabed and subsequent erosion hollowed out the softer strata. The result is a coastline that changes character every hundred metres, from sheer cliffs to pebble beaches to submerged rock gardens where damselfish gather in the shallows. Boat tour operators work from a shared jetty at the southern end of Agios Spiridonas Beach, where the monastery of Panagia Paleokastritsa overlooks the bay. Departures run continuously from nine in the morning until seven in the evening during the summer season, with each circuit lasting between sixty and ninety minutes depending on sea conditions and the number of stops. Most captains speak enough English to narrate the route, and a few offer sunset circuits that time the return leg to catch the light over Angelokastro fortress on the ridge above.