A castle from the Holy Roman Empire that hosts traveling youth... in its stables.

The prototype for all Nazi concentration camps.

This medieval castle overlooking the Elzbach river looks just like it did hundreds of years ago.

The fairy tale castle of the "fairy-tale king."

Bubbling up from deep underground is the warm crystal clear water that fills the Warm Springs Pools, America's oldest spa.

These unusual rooms on wheels are holdovers from the 1960s.

The Pentagon sits on a former island that was in Virginia at low tide and D.C. at high tide.

The story behind the mysterious symbol painted in front of the historic university's famous Rotunda.

The romance of early commercial flight still fills this Art Deco destination.

A former major munitions plant that has been converted into a sprawling art space.

An enormous warehouse filled with parade floats collected from over 50 years of patriotic celebrations.

This isn't your average roadway—it's actually a National Park and a transportation pioneer.

A bunker "with enough U.S. currency to replenish the cash supply east of the Mississippi" in the event of nuclear war now protects nitrate film.

Forget Hollywood, one of the biggest stars in the world can be found in Roanoke, Virginia.

The Virginia farm where John Wilkes Booth met his grisly end is now largely forgotten.

The semi-reclaimed ruins of this canal were once part of an ambitious plan to reroute the mighty potomac.

One street divides a single town that stands in two U.S. states.

The only recreation of William Shakespeare's indoor playhouse.

At 207 feet, one of the world's longest continuous escalators.

One of the last active volcanoes on the Eastern seaboard.

This historic mansion was built as a symbol of love between a husband and wife.

A small Richmond island dotted with the remnants of hundreds of years of history.

The final resting place of two (or three) presidents, one vampire, and 18,000 Confederate soldiers.

The ruins of this Thomas-Jefferson-designed mansion have been left to crumble since the Christmas Day they burnt down.