This sculpture by artist Fritz Keonig survived the 9/11 attacks and now stands as a monument to the victims.

Quirky water tower advertises the long-gone Brooks Tomato Products Co.

Once one of the world's great cities, Cahokia was a place of religious worship, trade and mass human sacrifice before being mysteriously abandoned.

The monument's pointy aluminum tip has been melted down by repeated lightning strikes.

The remains of Martha, the last known passenger pigeon, serve as a tool to educate about conservation.

The actual model from the original "Star Trek" series is now on display at the National Air and Space Museum.

A tiny piece of the Moon is embedded in this stained glass masterpiece.

Once America's tallest structure, now a Baltimore landmark.

The trials and tribulations of marking Poe's grave.

The statue of John Harvard isn't actually John Harvard—or even, technically, the founder of the school.

This nearly endless university hallway is home to a unique sunset known as "MIThenge."

This bridge was the birthplace of a unit of measurement based on a fraternity joke.

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

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

Ice cream stand, snack bar, and time capsule of milk conveyance.

The site of one of the strangest disasters in history—a wave of deadly molasses traveling at 35 mph.

This historic Boston building has gone from personal estate to porn theater and back again.

Mrs. Mallard and her brood are a beloved fixture in Boston Public Garden.

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

19th-century operating theatre in which the use of ether was first demonstrated - plus, a skeleton and a mummy!

This landmark cemetery in Boston was created more than 300 years ago.

This ambitious father and son team reigned supreme over the North End, and witches, for many years.

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

Macabre headstones carved with winged skulls, dancing skeletons, and pithy reminders of impending death.