A giant open-air sculpture made of over 200 full-sized boats.

The second-largest gold nugget in existence, displayed in a Las Vegas casino conveniently named the Golden Nugget.

Las Vegas's very own 40-foot-tall fire-spewing praying mantis.

In the middle of a busy airport, a statue honoring the astronaut who told Houston that Apollo 13 had a problem.

The Denver airport is guarded by a 32-foot-tall sculpture of a demonic horse.

A dedication plaque on this Boston tunnel is a microcosm of a massive, controversy-laden construction project.

The former home of a Boston physician whose murder led to a revolution in forensic science.

Dedicated to nine marines from Massachusetts who perished during the Beirut bombings.

Dedicated to a colonial woman who was hanged for being a Quaker.

A stone marker commemorating the first time sound was transmitted over wires.

Created by a local artist, these quirky sculptures each have their own names and personalities.

A luxury hotel constructed out of a former jail.

What was once a true peninsula has now been filled in, causing the water to recede and leaving many streetside "waterfronts" and landlocked "islands."

A tiny plaque marks the location of the water source that facilitated the birth of modern-day Boston.

Stolen goods adorn the organ at Old North Church.

Dedicated to one of the darkest moments in Irish history.

This area was once known for being a lawless haven for rough-and-tumble sailors, earning the maritime-themed nickname "the black sea."

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

This parking garage was the site of what was - at the time - the largest cash robbery in history.

A mysterious stone embedded at the base of a historic Boston building.

This historic patch of real estate offers a glimpse of colonial Boston.

This massive tea kettle was once a promotional stunt for the Oriental Teashop.

A more than 260-year-old crypt built on Boston's oldest English burial ground.

Narrowest house in Boston.