This obscure walkway links Edinburgh’s Old Town with one of the city's prime vantage points.

17th century streets hidden under Edinburgh were once a breeding ground for the black death.

A scattered trail of street art adds a pop of color to the city's stark structures.

"Respectful to the dead, safe and sanitary to the living, dedicated to the Genius of Memory..."

The abandoned transportation hub hides within the Glasgow attraction it once served.

A 200-year-old collection of oddities and medical paraphernalia.

A 300-year-old tea shop that brought tea to the English people, not to mention the Queen herself.

One of the few remaining casualties of the London Blitz, this destroyed church has become an enchanting public garden.

London's creepiest cemetery was once the site of dueling magicians and mobs of stake-carrying vampire hunters.

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the Harry Potter films.

This pedestrian walkway cuts through a cemetery and over several burial vaults.

Recently restored menagerie of Victorian-era beasts.

When the plague struck York, this stone was used to leave supplies for the sick.

Semaphore saints, a golden dragon's head, and a stone carved with religious warnings all call this cathedral home.

One of the shortest streets in York has an especially odd name.

This network of narrow, medieval passages has the most delightful name.

A century-old tradition has culminated in a small but singular collection of feline effigies.

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

More than 7,000 gallons of water pour over these cascading red quartzite waterfalls every second.

At the time of its completion, it was the tallest dam in the world.

Modeled after a famous church in Vienna, Austria—but in Helena, Montana.

This Yellowstone geyser may not shoot as high as the nearby Old Faithful, but it erupts for considerably longer.

Creek water that starts here has a 50/50 chance of ending up in the Atlantic or the Pacific.

The first declared National Monument in the United States.