The history of those incarcerated in Singapore during World War II is etched into the bricks of a popular staircase.

This statue once earned the distinction as one of the "Three Major Disappointments of the World."

A former reservoir that was only recently discovered after more than 60 years of disuse.

A historical convent known for taking in bad luck babies left on its doorstep is now an upscale shopping center.

One of the largest Chinese cemeteries outside of China spent years overgrown and forgotten.

The busy transport hub is home to the tallest airport slide in the world.

This Singaporean food-court stall was home to the world's cheapest Michelin-starred meal.

The highest pedestrian bridge in Singapore looks like a series of undulating waves rising between two public parks.

This rare wildlife haven in Singapore feels like you're in the tropical rainforest.

Terrapins of all colors and shapes are quick to bring fascination (and possibly long life) at this museum.

This $62 million dollar temple was erected to house one little dental fragment of religious history.

The largest pool at its elevation sits on top of one of the most expensive resorts in the world.

Singapore's landscaping project is home to 18 incredible Supertrees.

A completely underwater art museum sends a stark message about humans' impact on the environment.

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

Stunning Roman aqueduct used for 1900 years and still standing.

Mysterious Spanish catacombs of unknown origins.

Step inside the first house designed by Catalan architect Antoni Gaudí, considered to be one of the first Art Nouveau buildings.

This Navarrese cave's history of witchcraft and pagan ritual is not just embraced, but recreated each year.

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

Barcelona's historic 19th-century sewers, whose foundations were laid in medieval times, are open to the public for exploring.

Hundreds of stone stairs and a winding medieval bridge connect this haunting Spanish island to the mainland.

Wonderland replication in progress by one persistent man.

A museum dedicated to the Spanish occult in a town that was terrorized by the Inquisition.