This unmarked and unloved Manhattan subway grate created one of the most iconic images in American cinema.

The original toys that inspired the beloved children's stories are on display at the New York Public Library.

Elevated freight railway turned wildly successful urban park.

The curious underground history of keeping Paris clean.

A blooming house of worship for the masses.

A memorial to the nearly 10,000 American soldiers laid to rest on the beaches of Normandy during WWII.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.

Flames have been burning within this mountain for more than 2,500 years.

The ancient latrines of the Greeks, in all their public glory.

Roman ruins, natural methane fires and a lovely beach.

In this historic region, homes and churches are carved into ancient volcanic rock formations.

This representation of Lord Vishnu is the largest stone sculpture in Nepal.

The oldest Hindu temple complex in Nepal serves as the seat of Nepal’s national deity, Lord Pashupatinath.

Towering at a height of over 30 meters, this turn-of-the-18th-century landmark is the tallest temple in Nepal.

The former stronghold of the Malla Dynasty has remained virtually unchanged since the 17th century.

This historic square in Nepal is home to temples dating back to the third century.

Jumping-off point for a climb up Mt. Everest is the most dangerous airport in the world.

Last stop before the top of the highest peak in the world.

A Himalayan monastery claims to have a piece of a centuries-old abominable snowman.

One of the largest Buddhist stupas in the world keeps an eye out in every direction.

This elegant neoclassical garden is a peaceful oasis in the middle of the Nepalese capital.

Sacred Buddhist home of some spiritual monkeys.

The intricate stonework of Machu Picchu serves as a testament to Incan engineers.