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

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

A Norwegian-born sculptor created these soaring guardian angels at the entrance to Hoover Dam.

These markers are used to document elevation changes around the famed dam.

The location where the iconic movie character declared it was time to go home.

The marker offers a rare chance to be in four U.S. states at once, though there's some controversy over its geographic accuracy.

The phrase "the shot heard around the world" was coined after a skirmish at this bridge.

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

The highest point in New Jersey is marked by a massive, if simply named, obelisk.

On the Hudson resides one of the largest clocks in the world.

This haunting monument honors the victims of 9/11.

Spies, love letters, and ghost stories have all left their mark on this home-cum-museum.

This hidden oasis features a stunning view of the Hudson River and the Palisades from a castle-like museum.

Mysterious 500-year-old tapestries depict a unicorn hunt.

Curious crustaceans support an obelisk from ancient Egypt that now stands in modern-day Central Park.

Once the tallest building in the world and the site of "the highest dinner ever held in New York" this building now holds the most expensive penthouse in the city.

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.

Michael Jackson got Bad and Crocodile Dundee walked on heads in this iconic Brooklyn subway station.

This Wall Street bar was once a hub of revolutionary activity where Washington famously bid farewell to his troops.

Deliciousness abounds at a Guatemalan restaurant masquerading as a pizzeria.

A monument to the military service of America's greatest traitor refuses to even name him.

Rising out of a clearing in New Jersey's Pine Barrens is an Aztec-inspired monument to the "Lindbergh of Mexico."

This Great Depression-era creation was once known as the strangest house in the world.

This 25-foot-tall gorilla made his way from the Wildwood boardwalk to a Pine Barrens gas station and deli.