A 1,215-foot tunnel transports pedestrians beneath the River Thames.

A hands-off space for graffiti artists to hone and display their skills.

An unusual round church in London with a Templar past.

A student driver's nightmare.

A charming 17th-century alley is lined with secondhand bookstores and antiquarian shops.

Banksy gives themself artistic license with this piece of London street art.

The perfectly preserved underground rooms where Churchill plotted the war against Germany.

An easily overlooked stretch of ornate window fronts and gaslight lamps that could be right from the pages of Dickens.

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.

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

This working class sculpture pounds his hammer all the livelong day.

Though strikingly beautiful, Seattle's other railway station is now largely forgotten.

A wall of chewing gum moonlights as collective art.

This former coal gasification plant found a curious second life as a popular public park.

A museum dedicated to the history and exploration of both popular music and science fiction.

Golden and naked, the figure that was once the highest point in New York is all that remains of the second Madison Square Garden.

This elaborate towering structure was once famed for its revolutionary height.

Yo, Adrian!

Huge masonic hall in Philadelphia with lavishly themed rooms.

World's first "penitentiary," meant to be humane, drove men insane.

Millions of numbers carved in glass represent the tattoos forced upon victims.

A former waterfront market is now in the center of town due to some interesting Boston engineering.

This monument on Breed's Hill proves that one of the most famous battles of the Revolutionary War is misnamed.