One of the few remaining ancient aqueducts described by Frontinus as 'the most solemn testimony of the Empire.'

A stone slab in Madrid marks the point from which the distances of Spain's national roads are measured.

Over two centuries old and counting, Madrid's massive botanical garden contains one of Europe's only desert environments.

The earliest known map to show America, discovered by accident at a Paris bookshop.

Madrid's romantically ornate crystal palace has been offering shelter to plants and art for over a century.

An ancient Egyptian temple in the middle of Madrid, Spain.

The oldest restaurant in the world is this old-world Spanish eatery, still known for its suckling pig.

Part of the medieval watchtower is displayed in an otherwise ordinary parking garage.

A rare set of strings by famed instrument maker Antonio Stradivarius is on display in the Royal Palace.

Once a strategically imperative naval base, portions of this Bermuda dock complex now serve cruise ships.

The abandoned Bermudian home of a British naval leader is surrounded by crumbling sporting fields and the graves of convicts.

The world's smallest drawbridge.

Storms, funding, and in-fighting have kept this Bermuda church from ever being completed.

Thanks to modern navigational tools we now know that the true prime meridian runs through a park next door.

Eighty million natural history specimens call this gargantuan museum home.

This massive collection of British military artifacts includes the heartbreaking personal letters of the men in the trenches of WWI.

Scattered throughout London are ancient remnants of the city's former bounding wall.

London's smallest police station is barely the size of a phone booth.

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

Hear the quietest sound from across the dome.

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

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

This collection of bronze hands comes from astronauts, presidents, baseball greats, and more.