This now-defunct synthetic fuel plant was once a major cog in the Nazi war machine.

The last king of Poland was interred in this church nearly 200 years after his death.

In northeastern Poland, the ruins of a massive granary overlook the Narew River.

This 13th century Gothic brick castle is the largest in the world by surface area.

This home designed for chocolate magnate Antoni Amatller is an exquisite treasure-box of Catalan Modernism.

This Underground station has been a popular filming location for decades, even before it closed.

In this medieval fish bowl, the carp weren't pets.

Chelsea's soldiers were given strict orders when crossing this historic bridge.

The wreck of a B-29 Superfortress now stands as a memorial left in the moors.

The house in the middle of the motorway.

This park and coal mine heritage site is home to two of the last steam winding engines in the UK.

A well preserved remnant of the English Civil War.

This iconic building was founded as a school for the impoverished, but became one for the sons of the local gentry.

Austrian and Germans who died on British soil during World War I and II are buried here.

The longest and steepest staircase locks in the United Kingdom.

Also known as "Robin Hood's tree," this tree became a famed location along Hadrian's Wall before it was cut down in an act of vandalism.

A rather grand, but tiny, folly on the banks of the River Wear associated with a Polish count.

A 2,000-ton rock resting in a state of a delicate balance.

These lamps were created to expel sewer gases after an event known as The Great Stink.

A Victorian marvel of engineering is now a 21st-century tourist attraction.

The Great Fire of London and the regulation of one-way streets both started in this alley.

Named after a lodging site that existed nearby, a bridge has existed at this location since 1455.

This amazing example of Valencian Art Nouveau looks more like a cathedral than a public market.

A historic Christian shrine nestled within a spectacular natural cave.