The home of possibly the least-loved U.S. president stands as a sort of unpopular Monticello.

Don't get it twisted: This is the oldest pretzel bakery in the United States.

These tourist trap caverns are said to be the former home of a legendary Pennsylvania Hermit.

An Italian restaurant became a rock-and-roll hangout and the lair of the "Hollywood vampires."

This Hollywood dive houses a mural painted by the artists who animated its namesake film.

Outposts of this restaurant chain were shaped like jaunty chapeaus.

A world of craftwork elegantly curated in a historic brick warehouse.

An entire city block built completely out of petrified wood.

Elevated freight railway turned wildly successful urban park.

From a T-rex to a teapot, a cast of artificial fossils illustrates New Mexico's history.

A tunnel that brings more than a century of history to life from the deepest parts of the Niagara Gorge.

The smallest bar in Amsterdam has stayed in the family since 1798.

The future of roadside attractions is this sci-fi soda mecca that is home to a 66-foot tall neon pop bottle.

This unusually circular centenarian barn became a Route 66 icon.

This bright yellow relic is the final survivor of a short burst of seashell-shaped petrol pumps.

Outsider art meets paleontology at this roadside reptile repository.

A failed piece of Orientalism has become the proud symbol of a community.

A house carved into a rock in the 1940s.

A detailed pachyderm supports Rome's smallest Egyptian obelisk.

The engineering wonder and pleasure dome of a much-maligned emperor still holds undiscovered secrets.

This ancient market is often referred to as the oldest shopping mall in the world.

An ancient Roman temple first dedicated to an emperor's wife is now a church.

A mysterious chasm in the heart of the ancient Roman Forum, the Lacus Curtius was once believed to be a gateway to hell.

These hut foundations are believed to be the residence of Romulus, founder of Rome.