Elevated freight railway turned wildly successful urban park.

A tiny museum housed in a New York freight elevator specializes in the "overlooked, dismissed, or ignored."

A chocolatier with a quaint museum showcasing the history of chocolate.

A former church transformed into a public library.

One of the largest underground systems runs under Canada's largest urban center.

The Victorian-era greenhouse is stuffed with tropical plants, and open 365 days a year.

A fragment of one of history’s most famous walls stands as a reminder of unity in a culturally divided city.

This crumbling industrial fortress has attracted daredevils, filmmakers, and historians.

The only example of a Paris Métro sign in use at a subway station outside of the French capital. 

This hidden park hosts a rogue’s gallery of eccentric architectural obelisks.

This 1920s Amsterdam neighborhood was built as a giant experiment in concrete construction.

Some 80,000 Delft Blue tiles line the inside of this Amsterdam walkway.

From Tintin to the Smurfs, Europe's greatest graphic icons are celebrated in a grand Art Noveau gallery.

This 1967 experiment in modular architecture was designed to be a new model for urban living.

A grand Gothic Revival basilica with stained glass depictions of Montreal's religious history has only one soul resting in its crypt.

A swaggering, monumental souvenir of the most extravagant party Montreal’s ever thrown.

Immortalized in bronze, this frazzled student will be glued to his screen for centuries.

A reconstituted ancestral village of the Huron-Wendat Nation.

You feel like you're in a forest, but you're actually walking amidst the branches and trunks of a single giant tree.

This public elevator links the lower city to the upper city of Salvador.

One of the few places in the world where visitors can walk alongside fossilized tracks from 80 different dinosaur species.

This recessed garden protects thousands of mountain plants by creating its own microclimates.

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

The ruins of an early-18th-century complex that could once house up to 12,000 horses.