Turning night into day in Victorian-era Austin to thwart a serial killer.

A grove of colossal man-made flowers built to collect the sun's rays.

Home to the largest urban bat colony in North America, estimated at 1.5 million bats.

One part antique store, one part curiosities hodge-podge.

This unique structure in suburban Austin is made up entirely of other people's castaways, and constantly changing.

These ornate arches show how the course of the River Thames has changed.

Originally built for London’s cab drivers, this bright green hut now serves anyone a hot drink or meal.

The last remaining example of the boatmen's perches that once dotted the south bank of the Thames.

The library houses an incredible collection of some of the world's most impressive books and manuscripts.

A labyrinth hides in plain sight at each of the city's 270 Tube stations.

This long-hidden space above Westminster Abbey now displays the battle gear of the legendary King Henry V.

Museum dedicated to the UK's first charity for abandoned children, with keepsakes of the mothers who left them behind.

Never actually a tree at all, this spot was the site of London's public hangings for nearly 600 years.

The 2,000-year-old beam is tucked within the pedestrian entrance to the old London Bridge.

Spitalfields' regal market goat is said to be a monument to the area's migrant population but most are pretty sure it's just a goat.

The last four extravagant street signs of London's historic banking street.

The fierce beast perches atop a pedestal marking where the historic City of London gates once stood.

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

A historic house left in "dramatic still life."

This eclectic, mosaic-clad home includes a bamboo ping-pong loft and a "Whispermaphones" intercom.

A medieval replica of King Arthur's legendary table, the Round Table hanging in Winchester Castle was decorated by Henry VIII.

This silent sentry in the crypt below a large Gothic cathedral is often knee-deep in water.

A mysterious shape catches the eye in this 16th-century painting.

The "lost friend” is the most famous of the six moai statues that were removed from Easter Island.