A self-proclaimed libertarian micro-state on a tiny bit of disputed territory between Serbia and Croatia.

This picturesque medieval monastery guards a small trove of historic treasures.

Croatia's "hairy stone" fortress is one of the most well preserved Istrian castles.

When Croatia became independent of Yugoslavia, the splintering governments left behind these concrete tunnels.

The complex has been abandoned since the Croatian War of Independence, barring a stint as a set for 'Game of Thrones.'

This truly palatial work of Communist-era architecture now sits crumbling on a Croatian beach.

Gargoyle head that brings good luck.

Once a state-of-the-art tuberculosis treatment spa, these ruins are now ruled by paintball players.

The remains of a sunken military ship wreck visible through clear water.

A musical instrument played by the sea.

An ethereal glowing blue ocean cave in Croatia.

Medieval museum built over Roman baths that features famous tapestries of a lady and a unicorn.

This charming cobbled backstreet is the most Instagramable street in Paris, much to the residents' annoyance.

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

A surrealist timepiece by the artist of melting clocks.

Stroll through retro Paris while shopping for old postcards and discarded doll heads.

"In the Dark" Restaurant in Paris offers dinner in complete darkness.

Walk upon the mementos of the dead in this Parisian courtyard paved with medieval tombstones.

A mechanized clock where a man fights off a dragon, crab, and rooster.

A museum of magic with a Sadist past.

Paris' linguistic guide to the international language of, yes, love.

A museum of carnival attractions where you are invited to ride the rides.

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.