Now abandoned, the first public health hospital in the U.S. saw more than one million immigrants from around the world.

This abandoned ironworks was once the most important military supplier in America.

These chunky stone towers out in Lake Michigan are the key to Chicago’s drinking water.

A giant bronze coil of feces is both a tribute to doggie defecation and a reminder to pick it up.

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

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

This whimsical Oz-themed park had a wonderful impact on the surrounding neighborhood.

This abandoned seaside fortress is now simply an imposing ruin being taken back by nature.

The location of the pie company that gave a classic toy its name is now a parking lot.

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

The site of Paul Revere's historic two lantern warning.

Historic Hull Street was actually the first street with a proper name in the Boston area.

A former waterfront market is now in the center of town due to some interesting Boston engineering.

The 340-year-old house that inspired the classic Nathaniel Hawthorne novel.

This abandoned psychiatric hospital once housed more than 4,000 patients in the middle of a quaint New England town.

"Gnome Chomsky" was once the largest gnome in the world, but is now simply tall for his kind.

The remains of the furnace and iron works that produced the massive Hudson River Chain still stand in the woods of New York.

An abandoned Gold Coast-era mansion once intended for the exiled ruler of Albania, who never arrived.

A former poultry store that looks like a giant duck and is one of the "seven wonders" of Long Island.

This 19th-century Hamptons windmill was once home to modernist painter Agnes Pelton.

A mysterious air force base built to resemble a Long Island fishing village.

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

This eclectic homestead is home to a miniature windmill and Connecticut's last tollbooth.

An eccentric playboy's astounding natural history collection.