The last operating synagogue in Afghanistan is run by Zablon Simintov, the last remaining Jew in Afghanistan.

Site where Moses may have received the Ten Commandments.

An unfinished tomb carved into a giant boulder in the Arabian Desert.

More than 100 monumental tombs carved into rock are preserved at this ancient Nabataean site in the Arabian Desert.

A battle between nature and architecture in the Cambodian jungle.

Within the Saudi Arabian desert lies a 2,000-year-old ghost town made of stone and mud.

Abandoned bridge hidden deep in the San Gabriel Mountains.

A tiny, unassuming park in Tampa that belongs to the Republic of Cuba.

The remnants of a failed socialist commune can still be found just off a California highway.

This famous city eluded concrete detection until the early 2000's.

Some of the tallest ancient American ruins continue to inspire awe and curiosity.

This Route 66 classic sports a giant fiberglass rabbit that you can ride.

A cave's rare beauty held a cavernous secret hidden underground.

The second-largest cave chamber in the world was discovered in 1898 by a 16-year-old and a friend known as "Pothead."

This geothermal hot spring hides beneath a slowly growing mineral dome.

A clear blue swimming hole with hidden caves, still unexplored.

A spring-fed pool so deep it's used for scuba diving as well as swimming.

Michael Heizer's masterwork in the Nevada Basin.

This massive geographical sculpture is so subtle, it's possible to pass by it without noticing.

An eccentric artist's abode in this small Italian town has been transformed into a surreal temple of mosaic madness.

The 40-foot-tall votive candle is the largest of its kind.

A collection of massive stacked rocks in Texas includes a snarky note on the benefits of modern technology.

A recreated Stonehenge stands in a country field, complete with Easter Island moai heads standing as sentries.

This sacred cavern, 400 feet deep, is home to millions of bats and an ancient burial ground.