1887 era Russian Orthodox church in Minneapolis.

Minnesota's oldest and deepest mine is now an underground physics laboratory.

Duluth mineral magnates built this charming art deco lodge to be their private clubhouse.

The largest university building in the West is a gothic masterpiece containing dozens of theme rooms based on different countries.

This futuristically sylvan church is a glass-enclosed marvel of modern architecture.

This weird abode has inspired everything from the "House On Haunted Hil" to a robot hunter's pad.

This hilltop park offers magnificent views and a Frank Lloyd Wright masterpiece.

Frank Lloyd Wright's most iconic home dangles over a Pennsylvania waterfall.

No one knows how many bodies are in this vault in a Chicago public park.

Built to house a chapter of the Knights Templar, this grandiose building is a relic of Freemasonry in Chicago a century ago.

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

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

A hollow cement depiction of time's inexorable effect on the human body.

An underwater city for the dead.

An enormous park-like oasis, full of famous Chicagoans' graves.

A haunting statue called "Eternal Silence" has quite the reputation among visitors with active imaginations.

A speakeasy takes on Chicago's drinking culture.

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