Sitting on an Italian hilltop is this surreal fortress built by the mad inventor of electrohomeopathy.

This grand mansion has starred in everything from Bones to Buffy.

This Big Sur waterfall drops 80 feet directly into the Pacific Ocean, and inspired the hillside house up top.

This charming cobbled backstreet is the most Instagramable street in Paris, much to the residents' annoyance.

A French chateau, failed utopian community, odd museum, and Stonehenge replica in rural Washington State.

Roman ruins top white travertine terraces formed by ancient hot springs.

2300-year-old Roman road connecting the empire.

Known as the "Dodo Manège," this carousel features a herd of animals that have disappeared—or may be gone soon.

This small town in the Netherlands has no roads but instead, miles of canals and over 100 bridges.

Stay in a room with a view... of the bottom of the ocean.

The former home of the Nobel Prize-winning American writer is now home to dozens of six-toed cats.

This former lieutenant governor's home is brimming with curiosities.

A historic 1890s architectural masterpiece with an iconic clock tower that, once open to the public, now faces an uncertain future.

The only "Egyptian" pyramid in Europe and the legendary tomb of Remus.

America's only nuclear missile silo open to the public.

The "Seinfeld" diner.

If drivers cross the rumble strip on this stretch of Route 66 at just the right speed it plays "America the Beautiful."

San Francisco Bay's ghost town.

A sculpture made of 10 Cadillacs as a monument to the "Golden Age" of the American automobile.

Sister store to the Echo Park Time Travel Store.

This massive redwood tree has a hole in the base big enough to drive through.

The lowest point in North America is home to an undrinkable pool surrounded by fields of geometric salt flats.

California's own medieval Italian castle, authentic down to the 300-year-old iron maiden in the dungeon.

This 16th-century monastery has been turned into a surrealist architecture compound.