The library houses an incredible collection of some of the world's most impressive books and manuscripts.

The artist and his brother are buried in a landscape straight out of a van Gogh painting.

Before it was buried by volcanic ash, this fast-food restaurant fed the hungry hordes of ancient Rome.

This ancient theater was once the home of fierce gladiatorial battles.

The industrial architecture honors the laborers who brought the Exposition Universelle of 1900 to life.

Museum on French naval history, with magnificent figureheads, a historic diving suit, and a boat used by Napoleon.

France's most famous cemetery, with some of its most curious tombs.

This massive library holds what was once the largest book collection in the world.

Remains of Roman amphitheater hidden in a sleepy quarter of Paris.

The remaining relics of the patroness of Paris lie in a chapel under a striking double spiral staircase.

The narrowest street in Paris.

Site of a classic 19th-century physics experiment to prove the earth is rotating.

An easily overlooked stretch of ornate window fronts and gaslight lamps that could be right from the pages of Dickens.

This gorgeous reading room houses the oldest and largest art history library in the Netherlands.

Ruined 11th century abbey built by King David I in Edinburgh, Scotland.

A verdant 17th-century-style garden hidden along Edinburgh’s Royal Mile.

This 16th-century close preserves an unusual piece of Edinburgh's transportation history.

This alley off Edinburgh's Royal Mile contains remnants of the city's seedier history.

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

The headless bodies of more than 1,300 guillotined victims of the Reign of Terror are buried here in mass graves.

This facility has manufactured stunning tapestries for France's royalty ever since the 17th century.

The city of Parma's cathedral is home to one of the greatest illusionistic frescoes of the Renaissance.

An incredible mosaic-lined monument said to have held the remains of an ancient Roman empress.

Italian poet Dante Alighieri is entombed in this small mausoleum in Ravenna, and his hometown of Florence has never been too happy about it.