A spooky juxtaposition of caves and graves gives this legend-filled cemetery a particularly haunting vibe.

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

A mysterious bridge over a sunken Roman road.

A magnificent winding road through a steep valley, with deep natural caverns at the bottom

Sometimes an island, sometimes a rocky outcropping connected to the world by a tiny suspension bridge.

This giant wooden treehouse within a sprawling garden has its own eatery.

The oldest residential street in Europe also features an optical illusion.

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

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

This massive steel pyramid can be entered by a set of jagged steps that let visitors stand in its heart.

A memorial for a young woman and her ghost, which are claimed to have caused countless deathly shipwrecks.

Hamburg's first legal sex work is relegated to a gated street that still does not allow pedestrian women.

This strange building looks like a medieval fortress crashed into a 1960s Brutalist office block.

Dancing skeletal figures pay homage to a medieval mural destroyed during World War II.

This sprawling Jewish cemetery is one of the largest in Europe.

The only microgravity tower in Europe can produce nine seconds of weightlessness.

The first geometric self-supporting spiral stairs in Britain are a truly beautiful sight.

A gorge full of caverns where early humans lived alongside cave hyenas, giant mammoths and wooly rhinoceroses.

Huge concrete structures designed as an early warning system for Britain to detect enemy aircraft.

Drink your espresso at a Victorian-era urinal in this underground-restroom-turned-coffee-bar.

This logic-defying 16th-century Tudor manor still stands to the delight and astonishment of onlookers.

A statue of the legendary Celtic warrior queen who fought the Roman invaders stands in one of the cities she once destroyed.

Walk inside a half mile long crevice right outside the town of Garmisch Partenkirchen.

Carved fountains poignantly placed in parks and in front of special monuments.