The last street in Pittsburgh that's paved with wood.

This restaurant offers a side of antiques, curios, and a bathroom chock full of owls.

An 18th-century Catholic church converted into an eccentric temple of music and bacchanalia.

When oil was discovered just outside of Pittsburgh, the city became home to this regional stock market.

This quarter-mile tunnel under the Bluff in Pittsburgh bends at a 45-degree angle.

Home to the largest urban bat colony in North America, estimated at 1.5 million bats.

One of the most photographed buildings in a city known for its Modernista architecture is an abandoned squat.

Living towers made of people that are now recognized by UNESCO.

This one has sailed five times as far as Sir Francis Drake's famous ship.

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

An unusual round church in London with a Templar past.

This Industrial Age architectural and engineering gem helps visitors and residents alike traverse Lisbon, “The City of Seven Hills.”

A king's pet, a pope's gift, an artist's inspiration, and a tragic shipwreck.

The final resting place of American icon Buffalo Bill, and a museum that aids in telling his tale.

Gargantuan home of Russian science.

A sculpture park of the tossed aside relics of the USSR, from Stalin to a massive Soviet emblem.

Moscow's most popular cemetery includes the graves of numerous cosmonauts.

The site of the little-known Pennsylvania battle that sparked the Seven Years' War.

Frank Lloyd Wright’s most iconic home dangles over a Pennsylvania waterfall.

The house that Frank Lloyd Wright "(shook) out of his sleeve at will" at the age of 86.

When zealous marijuana enthusiasts kept stealing the "Mile 420" highway marker, the State of Colorado got creative.

There has been an astronomical clock on this spot since the 14th century.

An uber-secure, windowless tower of doom in the center of Manhattan is an NSA spyscraper.

This valley of hot springs and boiling mud pots is home to the record-holding "Geysir," which originated the English word.