The bones of this aquatic dinosaur turned to opal over the centuries and the beast's remains were almost sold as jewelry.

The final resting place of a space program monolith.

Hot springs monkey spa in the middle of Hell's Valley.

The oldest working mechanical clock in the world.

Hear the quietest sound from across the dome.

The celebrated eyesore created by starry-eyed sweethearts.

This Hungarian castle was built out of cardboard and wood until it proved so popular that it got upgraded to stone.

Museum dedicated to the terror regimes of Hungary.

This Slovak bridge is known both for its connection to a national uprising and its UFO-shaped eatery.

The beautiful baroque library of the Hapsburg empire.

Large Hadron Collider and the Birthplace of World Wide Web.

The National Railway Museum in York is the largest railway museum in the world, attracting almost 1 million visitors per year.

Climb inside an iron crystal magnified 165 billion times its normal size.

Theme park featuring miniature replicas of European monuments.

From Tintin to the Smurfs, Europe's greatest graphic icons are celebrated in a grand Art Noveau gallery.

This collection of over 50 murals celebrates Brussels' rich history as the self-proclaimed home of the "comic strip."

A battle between nature and architecture in the Cambodian jungle.

Khmer Rouge's high security prison.

After the devastating 2011 earthquake, historic Christchurch begins to recover, starting with the pop-up Re:START mall.

A New Zealand communications tower stands as the tallest structure in the Southern Hemisphere.

One of the world's steepest streets seems to have houses sliding down it.

Highly spherical boulders on the shores of New Zealand.

New Zealand's epic shrine to all things puzzling.

Dolphins, ancient clams and hundreds of waterfalls make this one of the world's top tourist destinations.