Venice's "Island of the Mad."

As can be expected from a centuries old church built in a canal city, the undercroft of this house of worship is beautifully flooded.

This community on a small Venetian island has taken to painting their houses in bright neon hues.

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

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

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

Notorious artist squat renovated into legal studios.

Beloved bar home to musicians of all eras and reputations.

The only Bahá'í house of worship in North America and one of only a handful worldwide.

The subtle science of a master molecular gastronomist.

A Bibliophile's Dream.

A monument to the art of slicing people open.

Four glass boxes hover over 1,000 feet in the air to give visitors an unparalleled view of Chicago.

This museum housed in a former brothel explores the past and present of sex work in Amsterdam.

The world's only museum devoted to the wonders of fluorescence.

An Amsterdam street lined with antique shops each one dedicated to a different obscure collection.

An ancient passage filled with stalls selling used books, once frequented by Vincent Van Gogh.

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

This 22-floor tower's Skydeck offers panoramic views of Amsterdam.

A trove of tiny treasures hidden within a Florida park.