Park for free in the lighthouse lot, then get ready to climb to the top! Your ticket gets you into the lighthouse, two keepers' cottages and summer kitchen, PLUS the museum and the yellow cottage.
Had intended a tour of the museum and lighthouse but ticket lady said my girlfriend had to cover up as she had a 2 piece swim suit with a coverup on already. Nothing wrong with her attire as it was!
Don't pay to park in front of TybeeMuseum if there is room at the Light House parking lot just a bit farther down. It is free over there and the ticket covers both venues.
I was impressed with the lighthouse, but the staff was very rude. Don't expect ANY museum reciprocations to be honored, not even the Coastal Museum Assoc. (they're members). No interactive exhibits.