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

This fairy-tale, neo-Gothic church in the Azores is a world of magical realism.

Picturesque intersection of witchcraft and ancient Christianity.

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

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

A unique seaside cave where Aleister Crowley faked his own death.

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

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

The world's oldest bookshop still in operation.

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

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.

This memorial to the victims of the Romanian Revolution of 1989 is often compared to a potato on a skewer.

This hauntingly beautiful cemetery outside a medieval citadel is full of winding paths and ivy-covered graves.

Climbing to the top of the cathedral's bell tower offers sweeping views of these medieval ruins.

Nine centuries-old fortresses guard the walls of this medieval Romanian city.

This Transylvanian church has changed its denomination four times.

A memorial museum to the political prisoners who were held at Sighet Prison, once one of the most feared places in Romania.

A spooky spot along the road where things mysteriously seem to move uphill by themselves.

A fire once nearly devoured this gorgeous 14th-century Gothic cathedral.

Check out engineering marvels of the past at this unintentionally retrofuturist museum.

Romania's triumphal arch looks out over Bucharest.

A medieval church built up to defend its village.