Sloth rehabilitation center in the jungle of Costa Rica.

This Costa Rican topiary park is a surreal garden of unearthly delights.

Two Civil War-era cemeteries stuck between runways at the world's busiest airport.

Enormous lake at the bottom of a unique cave system.

A wonderful collection of fossilized dinosaurs and other creatures that roamed the landscape millions of years ago.

This 19th-century fountain's namesake animal isn't what you think it is.

Giant topiary dog once played a role in a terrorist bomb plot.

A landscape decorated with enormous skull sculptures.

Wonderland replication in progress by one persistent man.

This postmodern apartment block was designed to be a vertical neighborhood.

A model solar system adds a celestial touch to this suburban park.

This small museum tucked within a subway station holds pieces from Madrid's past.

This lucky bronze frog was gifted to Madrid by a casino.

An exact replica of a colossal Olmec head sits atop a pyramid within a Madrid traffic circle.

The lengthy skeleton of one of the tallest Spaniards of all time is on display in Madrid.

This funky former tobacco factory is one of the most striking examples of Madrid's cultural diversity.

This amazing abuela became a diehard metal fan late in life and an icon of Madrid's '80s rock scene.

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

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

A lush indoor jungle fills this bustling Madrid transportation hub.

The iconic boulevard is the perfect place to catch sight of a bicycling skeleton, a levitating Satan, or a chef with his head stuck in a pizza.

A former steam-powered mill from the 1800s is now an industrial park with a giant steel dragon slide.

Bask in the 19th century grandeur of an eccentric Freemason millionaire's private gardens.

Week-long block party becomes a competition for the best decorated street.