Where commuters walk through remnants of an ancient Greek necropolis.

Concrete strongholds stand guard over the Golden Gate.

Since 1973, this block has been home to the most concentrated collection of murals in San Francisco.

A collection of memorabilia from the Beat era in the back of a San Francisco bookstore.

A shop full of natural curiosities, carnivorous plants, and costumed taxidermied mice.

Oakland's beautiful monumental cemetery.

Julia Morgan's Moorish-Gothic labyrinth of fountains, trees, natural light and Oakland's notable dead.

A massive ultra-modern church presents a science-fiction view of Catholicism's inclusive future.

This tiny island is home to the world's largest colony of Northern gannets.

This bridge is the first to be made entirely from iron, but designed like it was still made of wood.

A stone obelisk towering over the surrounding countrysides beckons hikers across the rolling moors.

Hidden on the urban banks of a Manchester river are a series of abandoned waterside industrial sites.

Semi-precious Blue John stones have been mined in this cavern system for centuries.

The National Railway Museum in York is the largest railway museum in the world, attracting almost 1 million visitors per year.

Follow the original medieval paths that wind through this intriguing section of the city.

Ninety feet off the valley floor is an ancient dwelling put under protection of the U.S. government by Teddy Roosevelt.

This crumbling Death Valley mining complex was known for its use of giant, 20-mule team wagons.

Millions of years of oxidation make a drive down this winding Death Valley road surprisingly colorful.

Major tourist destination known for its bubbling mud-pools and hot thermal springs.

Tubing through a cave lit with glowworms is a magical underground experience.

After the devastating 2011 earthquake, historic Christchurch begins to recover, starting with the pop-up Re:START mall.

A New Zealand couple's shell-adorned home living room, now on display at the Canterbury Museum.

Twice a day this ancient path disappears with the tides, leaving the Holy Island of Lindisfarne out to sea.

This Scottish manor house is a lush relic from the life of a literary great.