The silly symbol for an underground protest group is now scattered around the city.

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

An underground city of salt.

Beneath Kraków Old Town's main square lies a hologram-filled medieval market vampire graveyard wonderland.

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

This centuries-old wooden wonder was built in less than a year and is one of Europe's largest timber-framed churches.

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

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

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

The medieval castle built as headquarters for the Pope's secretive Knights Templar.

The verdant mossy ruins of a Franciscan monastery lie in the remote Sintra hills awaiting exploration.

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

Elaborately carved to showcase the glorious wealth that the age of exploration brought to the Portuguese empire.

This once-forgotten oasis in the middle of Lisbon was first created over a century ago quite by accident.

"Portugal's Stonehenge" is made up of nut-like stones aligned with the heavens.