A large camera obscura, constructed entirely from digitally fabricated components.

Part modern art project, part traditional chapel, this see-through church is only substantial from the right angle.

This giant urban staircase was built to keep the city's brave fighting men from getting waylaid in the red light district.

This abandoned Belgian fortress is purposefully being left to nature.

Descend into the tunnels to experience the life of a coal miner.

This historical Netherlands fortress still bears the marks of its single siege.

This sprawling Belgian fort was once thought of as impenetrable but now it is simply an abandoned relic.

This small window display is dedicated to the noble carrot.

The deepest lake in the United States, and once the site of epic destruction that lives on in legends.

Hollowed out cedar log tubs set in an ancient towering forest.

An unoccupied lighthouse encased in layers of ice from the waters of Lake Erie.

Landmark dedicated to the plight of the American Indian in the 21st century.

These strikingly barren, rolling red hills were caused by bad farming practices.

A sacred site for Native Americans surveyed by George Washington and owned by both King George III and Thomas Jefferson.

Lost subway station nestled beneath Toronto's busy commuter line.

A well-preserved network of cavernous tunnels have spent silent centuries removing Toronto's waste.

Secret Swing.

Futuristic apartment blocks are the backdrop for Montreal surfers hangin' ten on the Habitat '67 standing wave.

The only recreation of William Shakespeare's indoor playhouse.

One of the steepest streets in the United States makes an intriguing challenge for cyclists.

A take-out restaurant that only serves cuisine from countries with which the United States is in conflict.

An organ located deep within a cave, whose "pipes" are the geological features of the cave itself.

A massive sustainable farm designed by the mastermind behind Central Park.

Beautiful hillside Vermont cemetery with amazing funerary art.