Twelve and a half miles north of Key West's famous Southernmost Point on the Overseas Highway (US 1), you'll find the tiny island of Geiger Key. Running alongside a starkly abandoned beach is a washed out road, never repaired after being irreparably damaged years ago by a hurricane.
Now a local oddity, Geiger Key Beach starts where Boca Chica Road abruptly ends, protecting unsuspecting travelers from driving too far down a road which exists only sporadically beyond that point. While stretches of paved sections still exist, they are impassible by automobile. For about half a mile all you can find is sandy, unkempt beach alongside the road, perfect for sunning or exploring the rocky shore.
After the initial stretch of sand and pavement (popular with runners, rollerbladers and strollerwalkers), a large barricade blocks your path, as beyond that point the pavement has been washed away entirely. Alongside the barricade stands an ominous (or exciting, depending on your outlook) sign: "Clothing optional beyond this point."
If you have children or you're offended by nudity, it's best to heed the sign's warning. Although not a popular or crowded beach by any measure, some people come here to sunbathe in the nude. It's the only legally sanctioned "nude beach" in the Florida Keys and many visitors, especially the locals, take advantage of the opportunity.
Alongside the naked folks you may come across, you'll also see a few makeshift structures; lean-tos made of branches, dens composed of stacked rocks and coral, all created by adventurous locals. People don't actually live in them, but if you walk for long enough you'll likely come across one. There's no way of knowing who put them together or when, but thanks to them and the still-eroding pavement, the abandoned beach at Geiger Key remains in perpetual evolution.