Rome's semi-secret peephole vista is also a former Crusader stronghold.

Medieval museum built over Roman baths that features famous tapestries of a lady and a unicorn.

A museum dedicated to linguistics, from how babies learn to talk to endangered and extinct languages.

Inaugurated in 1921, this is one of many statues in France dedicated to the people who died during World War I for their country.

Folklore and history carved into Brittany's coast.

A piece of outsider public art accompanied by a strange urban legend.

A museum dedicated to a unique ecosystem.

So many migrating birds roost on the bridge, it has a special summer speed limit.

The house where the famed outlaw was shot by a dirty coward is now a museum to the criminal's legacy.

The history of the treatment of mental illness, illustrated in all its gory detail, and housed in an asylum.

The fastest mail service in the west is tracked and memorialized along this 1,400 mile trail.

The first home of the doomed aviatrix Amelia Earhart.

One of the world's most definitive collections of musical instruments, spanning all cultures and historical periods.

Home of an evil witch famous within southern folklore.

Enormous lake at the bottom of a unique cave system.

For two weeks every June, fireflies in the Smoky Mountains perform an astonishing light show.

Even Henry David Thoreau found this glacial pothole irresistible.

These towering spires and glowing walls are carefully crafted from hundreds of thousands of icicles.