This lovely pocket park is one of the most under appreciated in D.C.

The Pentagon is so large that it was planned like a city, complete with internal highway infrastructure.

There’s a hidden military meme engraved on the World War II Memorial.

An overlooked memorial honoring the local Washington residents who died in World War I.

The hidden offices underneath Memorial Bridge have been locked up since 1976.

The national park was once a plantation estate.

The winding route passes through an enclosed alleyway, two tunnels, and leads to the White House basement.

Nothing says indulgence like a 1,500-pound chocolate castle.

This abandoned dream castle and its cemetery look out over the city that once inspired their creation.

Step into the courtroom to learn details of the only case in history where ghostly testimony led to a murderer's conviction.

The lasting remains of a historic spa.

Dedicated to the largest armed uprising in American history since the Civil War.

This former zinc operation has a 90-year toxic history.

A 21-foot-tall statue of a miner made of scrap metal stands in this West Virginia coal town.

This outdoor exhibit features a historic wooden dam once used to help boats navigate the Ohio River.

The largest piece of cut lead crystal adorned a grave for 75 years and is now the shining star of a glass museum.

In 1869, Swiss and German immigrants settled in this small town in the mountains of West Virginia.

This small West Virginia park is a land trust holdout against mountaintop removal mining.

A lone gunner's station is all that remains of a replica Spanish Fort in Florida.

A hidden beach at the end of a tunnel of mangrove trees.

Where manatees are the snowbird vacationers in these balmy Florida springs.

The largest retailer of seashells in the world.

Get up close to an F-4 Phantom flown in the Vietnam War at this Florida park.

After the attack on Pearl Harbor, rocks and fossils from every U.S. state were collected into a pyramid of national unity.