Ruins of a late 1950s Polish ski jump ramp in the middle of the city.

A tree planted by Marie Curie is treasured by the Radium institute that she set up.

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

A mysterious carving from 17th-century London seemingly depicts a young boy sitting on a bread basket.

This Viking gravestone carved in a rare runic style was dug up from a London churchyard.

An exercise in radical design and social living that became the epicenter of Soviet spy networks in London.

One of the greatest movie directors of all time lived and worked in this London flat from 1926 to 1939.

A fully functional, 200-year-old remnant of the time when Brixton was mostly fields.

It is still illegal to "quarrel" at this unlikely urban oasis built on top of an electrical substation.

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

A Roman spa buried deep beneath the City of London.

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

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

A network of concealed passageways lies within a busy London Underground station.

The pioneer of psychoanalysis spent the final year of his life here, still seeing patients on that famous couch.

An abandoned tank sits in an empty London lot as a symbolic middle finger to local city planners.

Deceased nuns were placed on stone chairs to decompose, while the surviving nuns prayed near the lifeless bodies.

Some call this eerie forest of crooked trees the "Bermuda Triangle of Romania."

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

London's only public statue of the much-married monarch adorns the gate to St Bartholomew’s Hospital.

Morocco's Argania trees are infested with nut-hungry goats.

The oceanic dumping ground where spaceships go to die.

Mysterious face-like images that appeared within an Andalusian house are surrounded by legends of the paranormal.

A Spanish town built into the cliffs.