Just over an hour from Tallahassee or Panama City, on Hwy 166, the 1300-acre Florida Caverns State Park on the Chipola River has fascinating caves unique to Florida. Eerie stalactites, stalagmites and flowstone (formed by water flowing over rock) fill the lighted caves, along with calcified shapes created over centuries as calcite has bubbled through the stone. You can take a 45-minute guided tour (adult/child $8/5; 9am to 4pm) with a volunteer. There are also campsites here ($20).
They've come up with some quirky names to describe the various rock formations in the cave, from 'wedding cake' to 'bacon'. Outside, the Blue Hole swimming area makes for a fun – if freezing – dip.