Favorite thing: Franklin County, where Apalachicola is located, is named after the great polymath Benjamin Franklin. The current courthouse is the result of a Depression-era project, the building completed in 1940 and designed in the Federal neo-classical (and monumental) style of the time.
Trinity Episcopal Church seems like a little piece of New England on the Gulf Coast. There's a good reason for that. Large sections of the church were "pre-assembled" in New York State, and then sent by steamer down the Atlantic Coast and around the tip of Florida to Apalachicola. It was dedicated in 1839 and is on the National Register of Historic Places.
I also read that the beautiful Post Oak tree in front of the church was planted in the year that the Church was opened.