The world-record holder for the longest bridge stretching continuously over water.

One day a year it is legal to jump off of this astoundingly tall bridge that spans an Appalachian gorge.

This colorful overpass is one of Bhutan's longest suspension bridges.

This bridge uses an inverted bowstring truss and is believed to be the only of its kind in the United States.

A favorite of Amelia Earhart, ranking among those rare bridges that can be crossed without changing sides of the river.

This long-hidden space above Westminster Abbey now displays the battle gear of the legendary King Henry V.

A subterranean relic of the Spanish Civil War hides below this picturesque park.

An old limestone mine transformed into a beautiful and unusual sculpture museum.

These medieval funerary monuments are now home to a colony of critically endangered vultures.

This 8th-century Bavarian monastery is home to an exquisite Baroque-era library.

A hidey-hole sandwiched between cellphone, DVD, and jewelry stores features Tibetan delights.

There are two legends behind the origin of this unusually tall sanitary structure.

A sapling of the legendary tree where conquistador Hernán Cortés sat and wept after an Aztec uprising.

This unique temple complex remains off the typical tourist trail.

This Gothic castle-like portal is a testament to the amazing craftsmanship of the navvies who built the railway tunnel.

This "floating railway" is one of the world's oldest monorail systems.

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.

This nature center has one of the largest collections of native raptors in the Pacific Northwest.

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

Two stunning 17th-century libraries and a cabinet of curiosities.

The enormous 250-room Vanderbilt mansion conceals hidden doors and secret passageways.

Legend says a witch conjured the world's third largest whirlpool to protect Scotland from a nasty pirate.

This centuries-old wooden wonder was built in less than a year and is one of Europe's largest timber-framed churches.

A desert in southeast Asia, complete with a beautiful lake covered in lotus flowers.