Paleokastritsa's limestone coast drops vertically into water that registers fifteen shades of blue depending on the angle of morning light. The six main bays form a natural amphitheater, but the true geography lies in the thirty-seven sea caves carved into the western cliffs, most accessible only by small craft during calm weather. Venetian sailors mapped this shoreline in the fifteenth century as a staging point for eastbound galleys; nineteenth-century British naval officers stationed at Corfu's garrison published the first detailed charts of the cave system in 1823. The name derives from the Byzantine Greek for "old castle," referencing a fortified monastery built on the promontory in 1228. Private boat charters depart from the main bay between eight-thirty and ten in the morning, when prevailing northwest winds remain light and cave visibility peaks. The Blue Eye Cave earned its designation from a submerged opening twenty meters below the entrance that funnels sunlight upward through clear water, creating an optical effect first documented by marine geologists in 1967. Tour operators follow a counterclockwise route: Paradise Beach at the southern limit, then north past the triple-arch formations at Arkoudillas, before turning into the cave belt that extends four kilometers to Agios Georgios. Water depth ranges from three to forty meters; the skipper cuts the engine near cave mouths to allow drift entry. The monastery of Panagia Paleokastritsa occupies the headland above the bay, its whitewashed arcade visible from two kilometers offshore. Monks have tended olive groves on the upper terraces since the thirteenth century; the current structure dates to 1724, rebuilt after a landslide destroyed the original complex. The coastline remains undeveloped beyond the main bay: eucalyptus and cypress grow to the waterline, and the rock strata expose layers of Cretaceous limestone in horizontal bands of ochre and gray. A Paleokastritsa private boat tour reaches seven named beaches and eleven accessible caves in a typical three-hour circuit, though routes adjust to swell conditions and passenger preference. Captains carry underwater masks for snorkeling stops at depths between four and eight meters, where visibility often exceeds twenty-five meters in summer months.