The mysterious canine hides atop a drain pipe on the back of the building, some say as a sneaky shoutout to Yale.

A surprising museum of 20th-century technology.

A New Jersey state park that was once Napoleon's brother's sprawling estate.

This Delaware River bridge is emblazoned with a catty slogan from a more prosperous time.

This tiny structure was built by the creator of the Brooklyn Bridge.

Amazingly, this old machine within the Resorts Casino still functions.

European castle ruins in an American state park are actually the product of death and grief.

The meeting of the northwestern corner of Delaware, the northeastern corner of Maryland, and the southern edge of Pennsylvania.

Long hidden under grime, the politically radical murals of a little known Yugoslavian master are finally getting their due.

Amid the bustle and noise of the Financial District hides a secluded garden oasis above the city streets.

For over 80 years, Mayan ruins stood proudly in a most unlikely location.

Glacial erratic or man-made dolmen? It probably wasn't druids.

This once-private estate is now a dreamy, meditative garden that's open to the public.

The largest known open fault in the United States is basically a giant natural refrigerator.

Collapsing castle on the Hudson river was once the storage site of military surplus business.

Six peaceful acres in a residential neighborhood dedicated to art and peace.

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

These World War I shooting range tunnels are now haunted halls of underground graffiti accessed through the roots of a tree.

An oasis of calm amid the chaos of the boardwalk, the museum traces the heritage of this beloved beachside amusement park.

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.

Amazing views of Long Island Sound can be seen from this mountaintop tower.

An actual piece of the Moon, brought down to Earth by Apollo 15.

This petite park lets visitors see and touch examples of fossilized dinosaur tracks.