This one-of-a-kind Roman arch is not actually dedicated to the god Janus.

This small, ancient Roman temple was once a church dedicated to the patron saint of penitents.

This curious, round temple is the oldest still-standing marble building in Rome.

The yawning maw of this pagan visage is said to bite off the hands of liars.

The only remaining arch of the oldest stone bridge in Rome stands in the middle of the Tiber.

The remains of this 2nd-century Roman temple are incorporated into a modern building.

More sculpture than building, this architecturally significant temple was built on the spot of Saint Peter's crucifixion.

Nassau Hall has served as army barracks, a museum, and played a key role in the American Revolution.

It would take 35 firetrucks to fill this enormous glacial pothole.

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

It looks like a whale, it's part of Yale, and it's best-known by a nickname you can probably work out for yourself.

A Yale University president wears full samurai garb in one of America’s oldest cemeteries.

A glimpse at Walt Disney's vision for a "community of tomorrow," in miniature.

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

Once forgotten, this strip of sand was a rare beachside haven for Black Americans in Atlantic City.

A decommissioned military complex that's now a modern industrial park.

What was once a vast naval cemetery is now home to nesting birds and pollinating bees.

One of the oldest log cabins in America is one of the last of its kind this historic Swedish dwelling remains a piece of living history.

Instruments, apparatus, and rare books all relating to chemistry and its related sciences.

A daily replay of the experiment that proved the rotation of the Earth.

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

This bug-eyed water wheel uses the power of the Sun to clean up Baltimore Harbor.

Tour the sci-fi-esque reality of governmental disease management.

This massive store is home to an eccentric collection of vintage, retro, and peculiar goods.