A 70-foot-deep ice cave formed by lava from Mt. Fuji on the edge of Japan's "Suicide Forest." 

Colloquially known as “piss alley,” this narrow street filled with tiny bars and barbecue stands looks like it was pulled straight out of “Blade Runner.”

A 20-meter (65-foot) robot towers over Tokyo Bay.

The oldest hotel in the world has been operated by the same family for over 1,300 years, even catering to samurai.

This stunning blue and gold room changed cities twice before becoming part of the Smithsonian.

A hidden gem on the lawn of the U.S. Capitol Building designed by landscape architect Frederick Law Olmsted.

Fittingly, America's museum of architecture is itself a magnificently designed old building.

A monument in Washington D.C. marks the spot from which all other roads were supposed to stem.

The 10,000 Torii shrine.

The magical, mossy forest that inspired Princess Mononoke.

A cavernous three-story, 43,800-square-foot basement that was forgotten about for 60 years.

Hot springs monkey spa in the middle of Hell's Valley.

A magical place that lets you play in and explore the world of Studio Ghibli.

The largest source of fossilized insects anywhere.

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

Red sandstone structures dominate this landscape, which has been inhabited for some 5,000 years.

This secluded aqua waterfall in the Grand Canyon is the perfect swimming hole, and the Havasupai tribe's fiercely protected natural wonder.

Most-visited and most-photographed slot canyon in the American Southwest.

This Philly landmark has a giant butterfly pavilion, three floors of insect displays, and withstood a $40,000 heist.

The oldest surviving botanic garden in the United States.

A throwback train ride transports passengers through one of the lesser-known national parks in the country.

The mounds at this site were reconstructed with the help of archaeologists and historians.

Once home to more than 50 displays of freshwater fish.

This ruined fort and statue are a testament to the last king of Kaua‘i’s savvy diplomacy skills, which briefly brought Russians to Hawai‘i.