Martin Bricelj Baraga's monolithic sculpture measures the blueness of the sky, and changes color to match it.

Castle and secret tunnel withstood a siege until its owner was killed by the Holy Roman Empire, while sitting on the toilet.

This one-time health resort was used by aristocrats around the world.

An eerie collection of the surviving structures from a past celebration of the future.

Replica of Seville, Spains famous Giralda, a former minaret converted into a bell tower.

The world's most elegant power lines.

Sanctuary on a ridge near an ancient shrine to a "Black Madonna" built by the founder of Opus Dei.

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

This mountaintop observatory is home to one of the world's largest reflective telescopes.

Lava stone structures possibly dating back to the 19th century may have been a stopping point for voyagers between ancient Egypt and the Mayan Civilization.

A modernist church in an ancient village.

For one day every month Barcelona's Estació de França transforms into a market for model trains.

This 47-story "M" needed 20 years to be completed

Remarkably intact Roman stone fortifications have encircled this Spanish city for centuries.

This former charity hospital for elderly clergy houses some of Seville’s most treasured paintings.

A medieval village holds a very modern hotel.

This "flat geyser" bubbles up out of the ground periodically like a disappearing river.

Thanks to an acoustic anomaly, this unassuming stone bench has heard one hundred years of secrets.

Geological storytelling.

Beautiful tiles decorate many of the town's surfaces and stand testimony to its glorious artistic history.

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

An impressive display of ships and artifacts from the ancient Mediterranean maritime trade.

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

The Gaudí-inspired building that was the start of Terrassenc modernism.