The longest-running seafood festival in Florida, held annually since 1963 on the first weekend of November in Riverfront Park. The town's population effectively triples for the two days. The big draws are the oyster-eating and oyster-shucking competitions, a Blue Crab Race, the King and Queen Retsyoyster pageant, and a Saturday morning parade.
It is a working-town festival rather than a tourist event — the local seafood industry runs the booths, and the proceeds fund local charities. If you are visiting Apalachicola anytime around early November, time it for the festival; lodging fills up months in advance.