Four glass boxes hover over 1,000 feet in the air to give visitors an unparalleled view of Chicago.

These pretty kitties killed and ate as many as 135 railway workers.

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

A 400-foot-tall tall map of Chicago makes this once-ignored building stand out.

Illegal drag racing two stories beneath Chicago’s streets.

An outdoor urban gallery of large-scale artworks by the world's most influential street artists.

A goddess-topped water fountain in Chicago was created thanks to the dreams of a thirsty newsboy.

This awkward aquarium sculpture is one of the strangest statues in Chicago.

An antiquated German apothecary on Chicago's North Side.

The world's only international cryptozoology museum is host to an unrivaled collection of mysterious objects.

In 1958, an MIT fraternity pledge laid down on this bridge and instituted a new, unique unit of measurement.

Dedicated to the neverending mathematical constant, this plaque next to a park bench was sponsored by an anonymous benefactor.

Harry Houdini plunged into the Charles River and performed one of his escape acts here in 1908.

This hidden gem of a garden has one of the only surviving Victorian ferneries in America.

This 17th-century house was once the trading hub for two prominent Canadian fur barons.

Former home of an abolitionist couple who escaped slavery and established the most active Underground Railroad stop in Boston.

This charming colonial alleyway is one of the oldest continuously used residential streets in the U.S.

Oldest existing church in New York and the inspiration for Washington Irving's "The Legend of Sleepy Hollow."

The real-life site of Ichabod Crane's infamous gourd attack.

This tiny patch of arid sand sits in one of the greenest states in the United States.

This nearly 200-year-old restaurant's history includes an exiled French prince, JFK, and a very hungry Daniel Webster.

Each August, one of the largest religious (and food) celebrations in the country is held in Boston.

Berthed at the Charlestown Navy Yard in Boston, "Old Ironsides" is the oldest commissioned warship still afloat.

This monument on Breed's Hill proves that one of the most famous battles of the Revolutionary War is misnamed.