The largest portal tomb in Europe has a capstone weighing around 150 tons.

An enigmatic monument to the Irish revolutionary who plotted an uprising against British rule.

A statue in the center of Dublin dedicated to one of their favorite sons of rock & roll.

More than 5,000 artifacts donated by the people of the city, plus a room entirely devoted to the band U2.

Dublin's "Dead Zoo" serves as a window to Victorian museum design.

Real bones which are said to have belonged to a Polish dragon.

The former Nazi concentration camp stands as a museum to remember this dark chapter in European history.

An underground city of salt.

A 250-year-old timepiece-automaton adorned with golden mechanical birds, which still sing to this day.

The oldest museum in Russia is home to a fascinating collection of nearly two million anthropological artifacts and anatomical curiosities.

An 18th century wonder of the world, lost in WWII, re-created at the Catherine Palace.

Moscow's imposing monument to the Space Age.

Former headquarters of the KGB.

Museum celebrating the achievements of the Soviet space program.

The gorgeous entrances into the city's underbelly look more like grand halls than subway stops.

A gas station and a state sign commemorating the most famous claims of extraterrestrial abduction.

The highest point in the state of New Hampshire, and while unlikely "the worst weather in the world," it sure seems that way to hikers.

The most photographed house in Maine looks good enough to eat.

The world's largest rotating world.

True to its name, this bouncy walkway may be the world’s smallest suspension bridge.

Elevated freight railway turned wildly successful urban park.

This evocatively named natural crevasse was created by a torrent of water that smashed right through a granite deposit.

Books you don’t need in a place you can’t find.

Macabre astrological automaton clock dating to the late 1400s.