The Argonaute submarine was the French navy's pride and joy in the 1950's.

An iconic and eccentric bar for "Manouche" Jazz music keeps expanding its space—and its influence.

The Sun King's military models, saved from the Louvre.

This bridge was constructed from the rubble of the infamous Bastille.

The oldest and smallest cemetery in Paris is only open to the public twice a year.

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

In this Parisian garden's grotesque former life as a zoo it fed exotic animals to the bourgeois and put humans on exhibit.

This little-known relic crypt holds stolen parts of a Roman Empress.

The floorboard scrawling of a tragic madman is on public display outside a Paris hospital, much to the dismay of its opponents.

BDSM, 1930s Style.

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.

Exquisite wall sculptures carved in secret by an early quarryman in an obscure corner of the Paris Catacombs.

A grotto-like lodge decorated with gilded mosaics, rocks and a noisy waterfall was the setting for the most sumptuous pleasure house of 1900s Europe.

This Parisian fountain is a little bit fantasy and a little bit nightclub.

The ruins of a Duke's bucolic dream, where camels once roamed alongside "Dutch" windmills and faux-Italian vineyards.

Paris' fabled purveyor of exotic taxidermy and natural history curios.

A majestic lion statue guards this Parisian botanical garden, and feeds on an unsettling item.

A subterranean shelter remains intact under a busy Paris railway station.

The history of radiation is on safe display at the foot of a radiation science laboratory.

Known as the "Dodo Manège," this carousel features a herd of animals that have disappeared—or may be gone soon.

Down a cobblestone alleyway is a museum dedicated to Romanticism, with a secret garden.

Statue of death tucked in the University of Medicine courtyard.

A museum on the history of Paris, including a set of Napoleon's toiletries, Proust's room, and relics of the Revolution.

This statue was given to France by the United States to commemorate the centennial of the French Revolution.