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

The house where John Wilkes Booth conspired with his co-conspirators.

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

The most decorated dog of World War I is preserved in the Smithsonian.

The beloved statue at the National Academy of Sciences is oh so inviting to sit on.

This lonely waterfront memorial to the men of the Titanic was erected by the "Women of America."

One of the largest underground systems runs under Canada's largest urban center.

One of the Seven Wonders of the Modern World holds the world's tallest metal staircase.

A 98-room castle in the middle of Toronto that bankrupted a 19th century electricity multimillionaire.

Willy Wonka would love this weird half-a-home.

One of the foremost Sherlock Holmes collections is hidden away at a Toronto library.

This massive, ancient stone was disassembled and then put back together again.

Soaring over the Niagara Whirlpool since 1916.

Once a black market electronics marketplace, now an otaku shopper's paradise.

The United States’s oldest funicular railway glides up and down a steep Pittsburgh street.

There aren't too many operational funiculars around, but Pittsburgh has two!

The largest university building in the West is a gothic masterpiece containing dozens of theme rooms based on different countries.

A massive Montreal stadium that has seen nothing but trouble since its inception.

Montreal's colorful subway station shows its support of the local LGBT+ community.

South Carolina's last remaining slavery auction house is now a museum devoted to its own tragic history.

Charleston's historic city jail once held everyone from pirates to Civil War POWs.

Dedicated to the history of the health sciences.

A traveling postal dog covered 48 states and more than 140,000 miles, and he lives on as taxidermy, patched up with a rabbit's foot and a pig's ear.

With over 100 jam-packed rooms to explore plus elaborate tea services and events, the Mansion on O Street is a hidden treasure.