Limestone caves with spectacular showcase chambers.

Come for the pizza, stay for a performance on the world's largest theater pipe organ.

A shining, cold, black organ lies in San Francisco's financial district.

From buttons to beads, flounces to fripperies, this textile museum and shop honors the history of needlework.

Check out a shovel along with your Shakespeare.

This towering church is home to a world-famous organ and a treasure trove of medieval art.

A little sculpture with a large wardrobe.

An overlooked memorial honoring the local Washington residents who died in World War I.

Look closely and you’ll notice that the color changes a third of the way up the tower.

The little-known, 300-year history of the area includes former lives as a bustling tobacco port, parking lot, and industrial dump.

The last living thing to come out of the rubble after 9/11 is now a symbol of hope and resilience.

Wall Street has a new heroine, a bronze statue of a small but fierce girl.

This mosaic dedicated to John Lennon was tended for years by a Beatles super-fan.

A private home built to resemble the shape of a microscopic creature.

This isn't your average roadway—it's actually a National Park and a transportation pioneer.

The graveyard holding the remains of George Washington's slaves was forgotten for nearly 200 years.

Hidden in plain sight on the Hudson River is an abandoned train station where nature has taken over.

This tall and trim architectural oddity is one of the skinniest buildings in San Francisco.

Longtime headquarters of controversial boys' club for the world's wealthiest and most powerful.

A unique market that brings together various goods and cultures.

Worker-owned cooperative and resource for those looking to lighten their ecological footprint.

The natural hot spring that was integral to the creation of Canada's first national park.

Though many were skeptical at first, these animal-specific routes across the Trans-Canada Highway have been a major conservation success.

This natural wonder is disappearing at an alarming rate.