The de facto symbol of Copenhagen is this bronze fairytale which cannot seem to keep its head for very long.

Stepping away from the glitz of mobsters and casinos to learn about the other history of Vegas.

A plaque marks the site directly below the mid-air detonation of the atomic bomb over Hiroshima.

This abandoned coliseum was intended to be a grand Nazi rallying ground before it was halted at the end of the war.

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

Pompeii's less famous neighbor is still revealing her secrets.

No telescopes, no power, no gift shop: The Observatory of Chichen Itza, one of the world's oldest observatories, takes astronomy back to basics.

The stones of this Incan wall complex fit together so well you couldn't fit a piece of paper between some of them.

An Aztec temple, the largest man-made pyramid in the world, sits buried in earth with a Spanish church set on top.

Installed in an act of one-upsmanship, the annual sundial in this church is also a symbolic victory for the Gregorian calendar.

The modern birthplace of Irish freedom.

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

Four alabaster giants contemplate the tides on the shore of Denmark.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

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

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

A wall of chewing gum moonlights as collective art.

This replica of the Greek structure is in the heart of Nashville.

The fairy tale castle of the "fairy-tale king."

A peculiar mansion built by the troubled heir to the Winchester Rifle Company fortune.

A desert that rolls right up to the ocean, where it's so dry animals live off the fog.

This "dead marsh" sits among the largest sand dunes in the world, a forest frozen in time.

Home of Howard Hughes' Spruce Goose.

Aqueducts have dramatically changed this old lake, now home to tufa towers and its very own species of tiny brine shrimp.