Catacombs turned marketplace.

The anatomical-pathological collection of a man who changed surgery.

In this cobwebbed old operating theater, you can practically hear the screams of the unanesthetized patients.

An incarceration museum on the spot of possibly the oldest prison in England.

The final resting place to 300 Victorian-era pets hides inside the city park.

A little slice of Japan and its aesthetics in London's Holland Park.

A historic house left in "dramatic still life."

The signs of a long buried road can still be found hidden beneath a London sewer grate.

A historic London cemetery now serves as a nature park incorporating gravestones & memorial statues.

This wildly-tiled artist's palace is a living and growing account of the creator's life, loves, and labors.

The Devil’s own choice when he needs a drink in Brussels.

Climb inside an iron crystal magnified 165 billion times its normal size.

Cozy basement bar sports an inventory of over 2,000 beers.

A little sculpture with a large wardrobe.

A fantastical 13th-century fortification sandwiched by a modern hotel in central Brussels.

Drink among marionettes at this pub inside a historic puppet theater.

A neo-Gothic church built to thank God for saving the Emperor of Austria from an assassination.

The water-powered carriages are long gone, but for over a century this funicular railway has been the fastest route to the highest point in Paris.

The final resting place for the remains of 143 Habsburg royalty.

Built to give thanks for the passing of a plague epidemic, this cathedral is a one-of-a-kind architectural hybrid.

A spherical "micro-nation" in the heart of Vienna.

A museum and shop on Bourbon Street located in the French Quarter.

This incredible collection of vintage pinball machines can be played at 25 cents a pop.

The decaying remains of a once-luxurious Soviet spa town.