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

High atop the Eiffel Tower is a small apartment built exclusively to entertain the science elite and make the rest of Paris jealous.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

This modest marker near Notre Dame identifies the very center of Paris.

A horde of stray cats rule in this secluded Parisian cemetery under a bridge.

This iconic Parisian bookstore doubles as the "Tumbleweed Hotel" for traveling writers.

A cluttered and astounding collection of antiquities and curiosities.

Hear the quietest sound from across the dome.

Hidden beneath the streets of London is a secret subway that only carried mail.

Eighty million natural history specimens call this gargantuan museum home.

The perfectly preserved underground rooms where Churchill plotted the war against Germany.

Kings Cross Station pays tribute to its role in Britain's best-selling book series.