The main reason to visit Guanica is the beaches. Take Route 333 south from the town to reach them. Caña Gorda Beach is the only one with facilities, but it's only open Tue-Sun.
From San Jacinto, just past Copamarina, you can also hop on a ferry excursion to Gilligan's Island (aka Cayo Caña Gorda), an undeveloped piece of paradise with white sandy beaches, snorkeling and mangroves.
San Jacinto, Road 333. Daily. Your basic beachfront shack, serving up cold Medallas and simple dishes of fish and chicken. Tiny beach with hammocks, great ocean views and sea breezes, and the ferry to Gilligan's Island departs from here.edit
Parguera — seafood and more beach, 15 km to the west
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