This beautifully verdant lagoon is tucked below a massive volcano in a crater atop a black pebble beach.

Spain's unique Mosque-Cathedral has been a place of worship for both Muslims and Christians throughout its history.

A stone slab in Madrid marks the point from which the distances of Spain's national roads are measured.

The Cathedral of Salamanca has a number of unusual carvings but none so surprising as a modern astronaut.

Visit a surreal landscape so otherworldly NASA actually used it to train the Apollo 17 crew.

In the fictional world of Kcymaerxthaere, celestial wonders marked a portal to a powerful route of travel at this site in Madrid, Spain.

The chefs at El Diablo use heat generated by an active volcano to cook the food.

Partially collapsed lava tube and cave system complete with concert hall, underground pond, and unique albino crabs.

One of the few remaining ancient aqueducts described by Frontinus as 'the most solemn testimony of the Empire.'

Madrid's romantically ornate crystal palace has been offering shelter to plants and art for over a century.

An ancient Egyptian temple in the middle of Madrid, Spain.

Natural stone arches form a walkable "cathedral" at low tide, then disappear entirely when the water returns.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

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

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.

This mosaic dedicated to John Lennon was tended for years by a Beatles super-fan.

Slyly buy a shake in the Parker Meridien lobby.

A pedestrian island in the middle of world-famous Times Square emits a strange (and purposeful) humming noise.

Elevated freight railway turned wildly successful urban park.

The rotting skeleton of a shoreside fun fair that was destroyed by fire and storms still haunts the Brighton ocean view.

A statue marks the exact spot where The Boy Who Never Grows Up made his first literary appearance.