Literally a million fascinating cartographic artifacts are held in this sprawling university collection.

One of Frank Lloyd Wright's final works was this UFO church.

Whimsical sculptures dot a woodland path surrounding their creator's old summer cottage.

A restaurant and lodge in northern Wisconsin which served as a clandestine hideout for John Dillinger and featured one of the most famous botched FBI raids in history.

This Native American cemetery features decades-old spirit house hidden behind pine trees and moss.

The secluded resting place of a local historical figure who perished during the sinking of the Titanic.

A subterranean world of tunnels links several buildings of this rare 19th-century asylum.

A simple midtown bar was once the home of a secretive and exclusive club staffed by "bunnies" under Hefner's strict rules.

The saddest little diner in New York.

Jimi Hendrix's legendary recording studio in Greenwich Village.

Residents of this Brooklyn neighborhood may be unaware their houses sit atop a buried trolley graveyard.

You must take the A train... to the last active cemetery in Manhattan.

A forgotten relic from New York's bygone trolley system hides in plain sight under a bridge.

This anonymous businessman sculpted in bronze became an enduring memorial after 9/11, and had been mistaken by rescue workers for a survivor in the rubble.

The last living thing to come out of the rubble after 9/11 is now a symbol of hope and resilience.

A strangely angled West Village home is the only monument to an explosion that took the lives of three American revolutionaries.

This subterranean oyster house has been the pearl of Grand Central Station since 1913.

A former connection to City Island, it has been abandoned since the 1930s.

The artist and New York City icon lived, worked and died in this converted carriage house owned by another iconic artist, Andy Warhol.

Feral cats keeping the rodent population at bay all across Greenpoint waterfront.

A little lighthouse in New York City, surrounded by mysterious stories of insanity-driven construction.

Beyond being incredibly fun, not much can be said about the Hole with certitude.

Combination beer garden and music venue in the heart of Wicker Park.

Chicago's North Park Village was once the largest municipal sanatorium in the country.