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

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

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

A hidden three-foot-wide house separates these two regal churches.

Elaborate tile work in this railway station tells the story of Portugal.

Ancient catacombs form the foundation for this Rococo orgy of a church.

The stunning interior of this Gothic church is covered in ornate gold details.

One of the most beautiful bookstores in the world hides a neo-Gothic interior behind an art nouveau facade.

This abandoned five-star hotel is now a five-star urban exploration destination.

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

This Industrial Age architectural and engineering gem helps visitors and residents alike traverse Lisbon, “The City of Seven Hills.”

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

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

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

This 50-foot-deep sinkhole created in the 14th century is home to rare plants and fungi.

The fishing boats that moor in this small lagoon enter and leave through a tunnel to the sea.

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

The floor of this spectacular Baroque sanctuary is covered in memento mori.

This spectacular dome managed to survive after being bombed in World War II, in an event known as the "Miracle of Mosta."

The Jesus tree of Malta bears a striking resemblance to Christ on the cross.

Burial grounds for more than 1,000 bodies deep under the modern town of Rabat.

This Stone Age solar temple aligns with the sun on each equinox and solstice.

An abandoned set from the 1980 film "Popeye," claimed and repurposed as a theme park by creative locals.

A stone marker and sculpture in the city of Riga stake a claim for the very first community Christmas tree.