A little-known subterranean street runs under some of the best-known buildings in Chicago's River North.

Former meatpacking facility turned vertical farm and sustainable business complex.

This $3 million model train takes you through Chicago, Seattle, and the thousands of miles in between.

A display of magnificent stained glass windows is the first exhibit of its kind.

All of Chicago's wood-paved streets are long gone but two alleys remain.

This unauthorized stone mermaid was secretly carved out of public stone before being permanently preserved.

A century-old network of freight tunnels underneath the city's historic business district.

This massive stained-glass masterpiece is thought to be the largest Tiffany dome in existence.

All that remains of the once-booming chain is a single orange-roofed restaurant.

A hidden bar inside an ad agency has a deliberately misleading name, so employees can stay late under pretext of paperwork.

A pop-culture attraction outside of Dyersville, Iowa, hits a home run.

For just a few bucks, this Iowa funicular will let you feel like an 1800s fat cat.

A giant pair of thick black glasses mark the tragic demise of a trio of rock and roll legends.

Hop on the train and tour an elaborate miniature town made completely of junk (including the train).

Under a playground is a little-known sealed train tunnel that likely contains the bodies of workers trapped by cave-ins.

The rogue roots are gradually consuming some of the historic marble grave markers.

A cement mixer-turned-kaleidoscope in downtown Norfolk offers different views of the city.

This maze-like slot canyon is a unique gem within an already fascinating geological area.

A railroad tunnel that, upon its completion, was considered one of the engineering marvels of the modern world.

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

The remains of a failed attempt at medieval nerdery are hidden deep in the woods of Virginia.

What was once a trend-setting, phrase-coining icon of architectural splendor is now a rotting, forgotten hulk.

The remote resting place of a notorious Wild West outlaw whose death is shrouded in mystery.

A partial tunnel blasted into a steep ridge is all that remains of a failed railway across Arizona.