Flamboyant architecture from the turn of 20th century.

A Parisian exterminator's shop whose storefront displays stuffed rats hanging from traps.

A 16th-century fountain marks the site of a lost medieval cemetery once filled with mass graves.

Executions were once held near this beautiful 18th-century fountain.

Noirish green neon marks the location of one of the oldest private detective agencies in France.

Shop at the 200-year-old store where Julia Child stocked up on copper cookware.

This small, ingenious cannon once helped regulate Parisian life.

This whimsical castle of grottoes was the labor of love of a French postman, and one of the greatest achievements of outsider architecture.

The remains of this castle, known as the Witch’s Eye, watch over the Thur Valley.

This museum is home to a sugar sculpture of the Berlin Airlift Memorial.

A fascinating insight into daily life in the Eastern Bloc.

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

Tiny memorials honor individual victims of the Holocaust.

One of the world's heaviest musical instruments towers within a popular urban park.

A historic fire call point.

A monument to the three wars that led to German unification towers within a Berlin traffic circle.

If you look closely at the oldest bridge in Paris, you might notice hundreds of ugly faces leering from its sides.

Notorious artist squat renovated into legal studios.

The spiral staircase hidden inside this giant Parisian column was likely built for Catherine de Medici's astrologer.

With a history of slaughter, feast, and famine, remnants of the pork industry decorate this area--even its church.

This former “ante-chamber to the guillotine” has been refurbished to illustrate the brutal history of French justice.

César Baldaccini's iconic sculpture of a 40-foot thumb stands tall in La Défense.

A cluster of cylindrical apartment buildings nod to the city’s vegital past.

This massive sculptural work outside of Paris was four decades in the making—and it's still not quite complete.