This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.

A building so large that it has its own weather.

Scattered throughout London are ancient remnants of the city's former bounding wall.

Synagogue built from the stones of Solomon's temple contains the golem of Prague.

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

A terrific purveyor of natural history objects and curios.

Explore the largest pure gypsum deposit in the world, and go dune sledding while you're at it.

Medicinal spa created with the discharge from a geothermal energy plant.

The intricate stonework of Machu Picchu serves as a testament to Incan engineers.

This iconic L.A. bookshop is housed in an abandoned bank—both symbolic and chic.

A walk through the historic city center, under the streets of Seattle.

An 18th-century lighthouse built on a 16th-century castle is now a monument to the maritime beacons of Scotland.

A desert island with both a buried treasure and a famous castaway.

A warning to the weak-kneed: This narrow bridge does its swinging eight stories high.

Ancestral Puebloan ruins, natural arches, and box canyons abound in this seldom-visited corner of Monument Valley Navajo Tribal Park.

See just what life was like in a 19th-century prospecting town.

This hidden stream beneath Indianapolis makes an appearance in the best-selling novel "Underground Airlines."

A solitary tree has grown up all alone on Lake Wānaka, backdropped by the beautiful Southern Alps.

A 300-year-old tea shop that brought tea to the English people, not to mention the Queen herself.

A tour of underground Berlin takes you through WWII air raid shelters and tunnels used to smuggle people out of East Germany.

This morbid, delightful curiosity shop offers everything from animal bones to human teeth.

Huge otherworldly domed rocks on the shore of a deadly lake.