Anne's Beach -- http://floridakeystreasures.com/Beaches/annesbeach.shtml at Mile Marker 73 -- is a quiet beach with a rocky shore and shallow clear blue waters. There's limited parking, but it's rarely crowded.
Stop for a picture with a giant lobster known as Betsy at The Rain Barrel Artisan Village, near Mile Marker 87. The popular figure of a crustacean is just one of many drive-by attractions on U.S. 1.
MARATHON: Sombrero Beach Park is a lovely community spot with a crescent-shaped beach, white sand and palm trees. Facilities include volleyball courts, picnic pavilions, playground equipment, restrooms and showers. No fee to enter or to park. It's open from 7 a.m. until dusk. To get there from the Overseas Highway, turn south on Sombrero Beach Road.
BIG PINE KEY: The Lower Keys have a more laid-back feel than the northerly islands, with fewer restaurants and tourist attractions. Signs warn you to slow down and watch out for Key deer, an endangered species. In Big Pine Key, you can see the small deer with white tails at the National Key Deer Refuge -- www.fws.gov/nationalkeydeer/. You can't feed them but you can watch them feed; you can also bike or jog here. To see the elusive lower Keys marsh rabbit, go in early morning and stay quiet by the tall grass.
You can also tour the Bat Tower in Sugarloaf Key -- www.keyshistory.org/SL-Sugarloaf-Key.html -- at Mile Marker 17. Just don't expect to see bats. The 1929 structure was built to lure bats as a way to combat mosquitoes. Bats stayed away, but the tower stands.
KEY WEST: Key West is known for beautiful sunsets, and the place to watch them is Mallory Square -- www.sunsetcelebration.org/.
At the Key West Historic Memorial Sculpture Garden -- www.keywestsculpturegarden.org/ -- you'll find 38 bronze busts of prominent men and women who had homes here, from Henry Flagler to Ernest Hemingway and President Harry Truman.
Finally, stop at the southernmost point in the continental U.S. for a picture at the replica of a large concrete buoy so you can say you were 90 miles from Cuba.