The oldest standing Byzantine church in Athens is tucked within a monastery in the middle of an upscale shopping district.

England's most famous front door has an accidental doppelganger.

An architectural oddity hides in plain sight on this iconic London bridge.

This unique bridge curls up like a caterpillar to let boats pass and then unfurls again to span a small canal.

A tiny replica of the iconic London landmark hides on the side of the steel structure.

One of the few remaining examples of 19th-century London’s attempt to clean up its reputation.

"We gonna rock down to Electric Avenue, and then we'll take it higher..."

On a wall in linear London, a plaque hangs at the high water mark of one of the worst floods in fictional Kcymaerxthaereal times.

These morbid carvings remind churchgoers of the inevitability of death.

The sculpture of the deceased cockatoo flops atop its personal plinth.

Where condemned pirates met their grisly end at the gallows on the River Thames.

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

A portly statue of a golden boy commemorates an unusual cause of the Great Fire of London: the sin of gluttony.

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

Murals of the wild parties once held on the frozen River Thames.

A monument to the thrice mayor of London who according to lore made his fortune by selling his rat-chasing cat.

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

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

These official units of measurement—including chains and perches—lie hidden beneath tourists' feet in a popular London hub.

Black cat statues guard this temple-like Egyptian revival factory.

This overlooked street light once served as a KGB dead letter box.

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

The wooden telephone box hidden away in London's Piccadilly was the original prototype of the iconic kiosk.

A memorial to a dog that inspired rioting in the streets of London.