A well-preserved network of cavernous tunnels have spent silent centuries removing Toronto's waste.

This museum is dedicated to a Hollywood icon.

Take an underground boat ride through a former hydraulic raceway that was built in the late 19th century.

A 22-million-year-old sandstone cave is a natural habitat for award-winning cheese.

Cool down and fill up after visiting Teotihuacán at this bar and restaurant in a deep, underground cave.

This mysterious medieval grotto holds a grid of sacred wells of unknown purpose.

The largest of the Fuji Five Lakes is home to an impressive swan population—some real, some with paddles, and one with an observation deck.

One in a pair of subterranean caves created by an ancient eruption of Mount Fuji.

This Japanese Manneken Pis gets new outfits for every occasion.

A lonely chimpanzee lures you into a narrow alley leading to this hidden shrine.

After a profound show of devotion for his master, a dog becomes the symbol of loyalty for an entire nation.

This massive, beautifully-lit underground quarry leaves visitors in awe.

Starship-temple contains 400 tons of drinking water and offers free Japanese lessons.

Museum showcases Japanese sexuality and some amazing ocean views.

A beautiful, dense forest in the shadow of Mount Fuji, with a tragic reputation.

The U.S. Supreme Court's secret Cold War relocation facility in the mountains of North Carolina.

This former factory has been transformed into a technicolor wonderland, where dozens of local artists have collaborated to create a real choose-your-own-adventure experience.

This 170-year-old Swiss guesthouse built into the side of a mountain is best accessed by a cable car.

The bizarre visions of H.R. Giger, tucked away in a Swiss medieval city.

The largest underground lake in Europe.

One of the world's largest pyramids stands within El Mirador, the "lost city of the Maya."

This nostalgic Russian museum is full of USSR cultural artifacts from the 1970s and 80s.

Built on the remains of one the Incas’ most important gathering spots, this square keeps the spirit of a fallen empire alive.

Situated on a sacred Inca site, this 16th-century cathedral took nearly 100 years to build.