A former barn converted into a massive train diorama.

A theme park attraction designed to turn your children into LARPers.

Shop of curiosities with a dinosaur museum tucked in its basement.

This sprawling mini-golf empire is an impressive testament to a disappearing attraction.

A six-story-tall golden pyramid, surrounded by a moat.

This $3 million model train takes you through Chicago, Seattle, and the thousands of miles in between.

A display of magnificent stained glass windows is the first exhibit of its kind.

These mansions date back to Chicago's days as a brewer's paradise.

This historic hotel invented the chocolate brownie.

A lush green oasis in the middle of Chicago.

A speakeasy takes on Chicago's drinking culture.

Each of these gorgeous, intricately decorated rooms is painstakingly crafted to the scale of 1 inch: 1 foot.

All of Chicago's wood-paved streets are long gone but two alleys remain.

This massive stained-glass masterpiece is thought to be the largest Tiffany dome in existence.

These old stone ruins in the Oregon wilderness were once bathrooms and are steeped in legends of murder.

The oldest certified bowling alley in the United States is in the basement of this century-old bar.

A house and yard adorned with bizarre concrete sculptures in a Milwaukee suburb.

A remote horde of architectural treasures fit for Indiana Jones.

These recently uncovered walls are all that's left of Washington, D.C's first defense contractor.

A rotating cast of guys and dolls in front of a Washington, D.C. building.

There's a crumbling old mansion inside the Smithsonian National Zoo.

The Byzantine, pre-Columbian, and medieval art at this stately mansion are some of the most under-appreciated collections in D.C.

The country's oldest continually-operated mini golf course lies hidden in plain sight, eclipsed by one of D.C.'s most popular tourist attractions.

A hidden gem on the lawn of the U.S. Capitol Building designed by landscape architect Frederick Law Olmsted.