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

An ancient and majestic fortress that played an integral role in Portugal's road to independence.

This unreal Portuguese palace looks as though it's made from a pile of different castles.

Legacy of the earthquake that nearly wiped Lisbon off the face of the Earth.

A 16th century chapel decorated with bones, skulls, and entire bodies hanging from the wall.

This eccentrically decorated palace is replete with grottoes, fountains, tunnels, and caves.

St. Mary's features one of the most spectacularly decorated cathedral interiors in all of Europe.

Polish luminaries and masterful folk art find sanctuary in this unique cemetery.

This man-made mound monument was built out of soil from all across the Polish empire.

Poland's oldest surviving university building holds a wealth of historic science instruments including some used by Copernicus.

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

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.

One of the most breathtaking railways in Europe also takes one of the steepest climbs, from fjord to mountain plateau.

One man's exploration of the human form, including the bizarre and delightful "Man Attacked by Babies."

A miniature city, once ruled by the Queen of the Netherlands.

These historic defenses ensured the city within would survive hundreds of years of occupations, sieges, and invasions.

Two geological phenomena in one precarious locale: a towering stone window, and a deep blue void.

Ancient mysterious ruts carved in the bedrock.

This unique building in the main square stands out among the city's typically Baroque architecture.

Stone Age solar temple is aligned with the sun on each equinox and solstice.

An expansive complex of subterranean tunnels is all that remains of one of Europe's most formidable medieval fortresses.

Legend has it that Napoleon Bonaparte fell in love with this Gothic church.