The tradition of open-air secondhand and antiquarian bookselling in Paris dates back to the Renaissance.

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

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

Rebuilt several decades ago, its striking murals prevent it from being reconsecrated as a church.

A scandalous Art Nouveau collaboration that set Paris all atwitter at the turn of the 20th century.

The first piece of public art dedicated to LGBT rights.

There must be a pun in this haystack somewhere...

Commemorating the spot where the famous scientist fed his pigeons.

Touching mementoes from those who didn't make it back from World War I still hang in one of New York's oldest bars.

Avoid gangster interaction while window-shopping.

The "Seinfeld" diner.

New York City's smallest piece of private property.

One of only two commuter aerial tramways in the United States.

Try not to get slimed in Tribeca.

A bit of retro transportation flair preserved in the world's largest department store.

This unreal Portuguese palace looks as though it's made from a pile of different castles.

This eccentrically decorated palace is replete with grottoes, fountains, tunnels, and caves.

A medieval house adorned with enigmatic carvings, including one of a man displaying his masculine attributes.

The narrowest street in Paris.

This surreal statue brings a famous French novel about a supernatural cad to arresting life.

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.

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

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

Elaborate tile work in this railway station tells the story of Portugal.