These mechanical goats first battled it out in the year 1551, all because of an overcooked deer.

An underground city of salt.

The walls and ceiling of this Polish church are decorated with thousands of skulls, with another 21,000 skeletons just below.

Museum dedicated to "the man who moved the Earth."

This unique railroad museum secretly contains the history of Poland rebuilding itself from the inside-out.

This Polish cave has housed a dragon, a brothel, and an enduring legend.

Warsaw's fantastically preserved gasworks...almost.

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

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

This open-air museum was originally a World War II testing ground for German missiles and rockets.

Mirrors and glass shards cover every inch of this arrestingly beautiful mosque.

The palace of the King of Kings, burned by Alexander the Great.

This magnificent blue mosque in Afghanistan is surrounded by thousands of white doves.

A spectacular rainbow of stained glass makes the "Pink Mosque" one of the most beautiful in Iran.

A long spiraling walkway winds through the woods, and around a copper beech tree at the center.

A preserved Nazi labor camp now has a Holocaust museum on site and memorials to the thousands that died while imprisoned at the camp.

There are two dozen tanks just sitting in an open field in Lower Saxony.

At this unusual park, domes, ladders, chairs, and more are made from trees.

It's good luck to be mocked by this monkey.

Thousands of flowers create enchanting pink tunnels over the city streets.

This museum tells the story of lake dwellers from 4000 BC to 850 BC, replete with stilt houses and goats.

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

This painted Lego bridge is the product of over a century of locomotive history.

Money made from smuggling sugar helped create this wondrous rock maze in honor of the Prussian Queen Louise.