Key West's Higgs Beach (more properly Clarence S. Higgs Memorial Beach) is just up the street from the better known Smathers Beach. Higgs Beach runs along Atlantic Blvd between the White Street Pier on the eastern end, and Reynolds Street on the western.
It has shady coconut palms, a wide sandy beach with long wooden pier you can walk down. Higgs Beach also has several pavilions, a volleyball net, and a restaurant right smack on the beach. It's a very laid-back vibe. Parking is free and if you can't find something, there is a larger lot up the street by Rest Beach.