An architect's childhood fantasy treehouse made real.

The oldest pub in Ireland may also be the oldest surviving bar in the entire world.

A classic Route 66 landmark that was built with scrap lumber and is held together with kitsch and puns.

The only runway directly into the magic kingdom has been closed since 1972, but it still sings to you if you drive fast enough.

Free public park and gardens filled with peacocks and peahens.

Once strictly off-limits, this lower level housing curious and priceless vehicles of the Petersen Automotive Museum is now open to the public.

In a city filled with Frank Gehry buildings, one stands out as one of the architect's weirder works.

Not merely a museum – but a whirring powerhouse that offers a subterranean peek into the heart and soul of cable car operations.

This unlicensed collection of fast-food memorabilia sits on the site of the first ever McDonald's restaurant.

A reliquary of pop culture marvels, including the world's largest (and most terrifying) Jack-in-the-Box.

America's Most Wanted's set resides in this tribute to the history of crime and punishment.

An uber-secure, windowless tower of doom in the center of Manhattan is an NSA spyscraper.

The secret city built by the Manhattan Project.

Megachurch turned Catholic church comprised of 10,000 glass panes.

The rusting remains of the largest assembled WWII fleet on the West Coast.

12,000 sq. ft. museum tracing erotic art from antiquity to modern times.

This replica of the Greek structure is in the heart of Nashville.

One man's vast collection of artifacts and ephemera from matchbooks and postcards to vintage neon signs and cars.

A new kind of theme park for adults off the Las Vegas Strip.

Located on 420 acres in the high desert, this spiritual center is dedicated to the "science of the future."

This ultra-modern home clings to the slope of the Hollywood Hills on a precarious stilt.

The last remaining relic of San Francisco's glittering 1915 Panama Pacific Exposition.

A world-class observatory in the California desert.

The only Bahá'í house of worship in North America and one of only a handful worldwide.