Couple's personal collection of pinball machines turned public pinball museum.

A museum dedicated to the history and exploration of both popular music and science fiction.

A walk through the historic city center, under the streets of Seattle.

Running under an entire mountain, the longest highway tunnel in North America is kept fresh using portal fans and jet fans.

This small city where almost everyone lives in the same building can only be reached via North America's longest tunnel.

This WWII-era military installation once held an entire city within its walls - now, its walls are falling down.

This expansive bridge in the Canadian wilderness was originally just built for friends.

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

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

Designed by Buckminster Fuller, this relic of the 67 Expo survived fire and ice.

This inexpensive lodging house was once a prison notorious for its inhumane practices.

Canada's subterranean Cold War museum has doubled as a movie set.

Elevated freight railway turned wildly successful urban park.

A building so large that it has its own weather.

Florida might be at its most surreal in this museum devoted to the famed Spanish artist.

An ancient system of freshwater caves filled with animal bones, including that of species long-extinct.

No telescopes, no power, no gift shop: The Observatory of Chichen Itza, one of the world's oldest observatories, takes astronomy back to basics.

A lovers' beach, tucked below the surface of the island, provides a safe haven for romance.