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

Picturesque intersection of witchcraft and ancient Christianity.

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

This gaping hole in the middle of a remote mountain lake looks like a portal to another dimension.

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

A submerged village appears when dam levels drop.

The world's oldest bookshop still in operation.

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

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

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.

Houses are tucked between, on, and underneath giant boulders.

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

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