There's a mini version of Iguazu Falls hidden in the Balkans, and it's got a rope swing.

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.

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

This small chapel is built of human bones and decorated with a golden skeleton.

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

This restored Portuguese cafe may well be the most beautiful place in the world to grab a Big Mac.

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

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

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

This unique architectural wonder is also tied to one of the 20th-century's most renowned writers.

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

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

The world's oldest bookshop still in operation.

Eat the ultimate iteration of Portugal's most beloved pastry.

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

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

A 98-room castle in the middle of Toronto that bankrupted a 19th century electricity multimillionaire.

Clap your hands at the base of the pyramid, and the song of a sacred Mayan bird will echo through the air.

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

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

Kissing the ass of this stone lioness has become a rite of passage in the city of Girona.

This stunning iron gate designed by Modernist architect Antoni Gaudí is filled with mythic symbolism.

The largest Art Nouveau complex in the world is a Barcelona hospital with a 600-year-long history.