Ancient barriers wrap around what was once an important stop along the Silk Road.

The foundation of this ancient stupa dates back to the 1st-century.

The first public building in Savannah to offer air conditioning was a luxurious cinema that still operates today.

One of Savannah's oldest and most haunted cemeteries, featuring graves desecrated by Sherman's Union Army.

A unique museum dedicated to the Gullah-Geechee people, housed within an old oyster cannery.

The remnants of the fortress that saved Georgia from the Spanish still stand guard on their swampy island.

Ruins of a Carnegie family mansion on Cumberland Island.

This 140-year-old beacon off the Florida Keys marks the wreck of a Navy ship that once roamed the Caribbean hunting pirates.

This lush Florida island is home to the ruins of a crooked ship breaker's tiny empire.

The largest freshwater lake in the Florida Keys.

Bat house that has only ever housed bat for one night; they all flew away and never came back.

The highway's southernmost spot is a beloved local attraction.

A monument celebrating the idea of reaching inaccessible places.

A nude beach alongside a washed-out road.

Island ghost town detailing Flagler's folly in building the Overseas Railroad.

Underwater art project will double as a massive artificial coral reef to help regenerate the damaged ecosystem.

Beach instrument turned bed and breakfast.

An island graveyard with spectacular views of the Caribbean.

Still standing despite its considerable slant, this tilted lighthouse has become a local symbol of resilience.

Few of the many visitors to this resort town know of its hidden Maya ruins.

Every equinox this Maya pyramid puts on a spooky ancient light show.

No telescopes, no power, no gift shop: The Observatory of Chichen Itza, one of the world's oldest observatories, takes astronomy back to basics.

If you can look past the nearby sewer pipes, this urban sinkhole grotto is a mini-paradise.

A flooded Mexican cave that hides a river beneath the water.