An alleyway plaque is all that remains of the independent Texas' envoy that forgot to pay their rent for over a century.

Wedged between two buildings at the Great Ormond Street Hospital is this secret music installation.

Hear the quietest sound from across the dome.

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

Several plaster noses are hidden in plain sight around London's Soho neighborhood.

A special shop catering to the needs of things that go bump in the night, and also helps kids become writers.

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

A subterranean ice warehouse that has lain hidden beneath central London for over a century is now open to the public.

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

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

This churchyard arbor is surrounded by hundreds of gravestones placed there by author Thomas Hardy.

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.

The popularity of Sherlock Holmes led to the creation of his fictional address, turning the orderly London street numbers askew.

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

Kings Cross Station pays tribute to its role in Britain's best-selling book series.

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

A towering monument to war, located on a beautifully peaceful hill.

A monument to the three wars that led to German unification towers within a Berlin traffic circle.

This curious sculpture represents the perseverance needed to take to the skies.

One of the world's heaviest musical instruments towers within a popular urban park.

This conical hill was built as a testing ground for an engineer known as the Glider King.

A restaurant and observation deck built in a unique broadcasting antenna.

Gardens representing parts of Asia, Europe, and the Mid East are tucked away among the Soviet-style buildings in East Berlin.