Frank Lloyd Wright built this suburban synagogue late in life, but it stands among his most iconic masterpieces.

The world's third-largest crystal sphere has sat in the Penn Museum since 1927 with the exception of one outlandish theft.

This hidden gem of a garden has one of the only surviving Victorian ferneries in America.

The internal railway of one of the biggest steel plants in America has been transformed into a linear park with unique industrial views.

Philadelphia boasts one of the best — and most often overlooked — traditional Japanese gardens in North America.

A nearly 25-foot concrete sculpture of Sylvette, Picasso's muse.

A contemporary fresco movement illustrates the region's rich history.

This steep cable railway has been hoisting passengers in the heart of Québec City for over a century.

The biggest museum dedicated to insects in North America, one of the largest in the world.

A daily replay of the experiment that proved the rotation of the Earth.

The sounds of the world's largest fully functioning pipe organ dazzle shoppers at a Philadelphia Macy's.

The oldest surviving botanic garden in the United States.

Dr Barnes' $25 billion private collection of art and arboretum.

The taxidermied remains of Charles Dickens' pet raven, which helped inspire one of Edgar Allan Poe's most famous poems.

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

The Netherlands' first car tunnel has an unusually rectangular shape.

'The Letters of Utrecht' lays out a ribbon of poetry one letter at a time, with no final verse in sight.

This narrow Ghent alleyway is an officially sanctioned street art tunnel.

Only museum in the world devoted to bookbinding and book arts holds a permanent collection representing five centuries.

Meet the bronze beloved pet to a family of famous peeing statues.

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

This collection of over 50 murals celebrates Brussels' rich history as the self-proclaimed home of the "comic strip."

This fairytale castle was built as a show of power but was nearly torn down thanks to its history of torture.

Take a stroll through the hellish grotesques of Hieronymus Bosch in this elaborate Netherlands church.