The largest of London's subterranean rivers and once a mad, bad center of London life.

This 1920s Dutch barge is now a floating bookstore.

A 2000-year-old Roman amphitheater lies just below Guildhall Yard.

The signs of a long buried road can still be found hidden beneath a London sewer grate.

The site of London's first coffee house has been serving refreshments of one kind or another for 360 years.

Rebuilt remains of a temple to Roman god Mithras.

An unusual round church in London with a Templar past.

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

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

Hidden beneath the streets of London is a secret subway that only carried mail.

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

A kaleidoscopic warehouse-maze of handmade neon signs.

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.

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

Every summer West Seattle experiences a housing bloom.

A busy cafe better known for board games than food.

This Seattle museum displays the history of the telephone through an impressive collection of telecom equipment.

A beautiful final resting place for some of the noteworthy deceased.

Couple's personal collection of pinball machines turned public pinball museum.

A colorful architectural gem in Seattle's uniquely modern Central Library.

Seattle's own bad art museum located inside Cafe Racer.

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

Home to secret Eastern Bloc spy equipment and the largest stretch of the original Berlin Wall outside of Germany.