At the very bottom of Florida, at nearly its most inaccessible point, you'll find the ghost town of Flamingo. Why you would want to find it is, well, up to you.
Flamingo was founded in 1892 as a settlement and farming operation, but something about the spot seemed cursed from the getgo. The farming failed, and the flamingo which was the town's namesake vanished from the area in 1902. The post office closed in 1909 out of disuse. Says Wikipedia:
Life in Flamingo could be very unpleasant. Leverett White Brownell, a naturalist, visited Flamingo in 1893. He described the village of 38 "shacks" on stilts as infested with fleas and mosquitos. He claimed to have seen an oil lamp extinguished by a cloud of mosquitoes. He also stated that flea powder was the "staff of life" and that the cabins were thickly sooted from the use of smudge pots.
The citizens of Flamingo persevered on, hoping that Henry Flagler would use the area for a proposed railway to Key West. He didn't. By 1910, only three homes remained occupied there.
Still, Flamingo clung to a tenuous existence. A gas station, restaurant and marina tried to serve what few tourists came passing through, and in 1959 an ambitious two-story hotel called The Flamingo Lodge opened. Not only didn't it work out, it was almost all destroyed in 2005 by Hurricane Wilma. All that chiefly remains of Flamingo now, aside from crumbling concrete foundations of old buildings, is its snazzy welcome center that welcomes nobody.