This giant temperature attraction created some giant electric bills.

A cavernous three-story, 43,800-square-foot basement that was forgotten about for 60 years.

Daredevil repair workers can worm their way out the access hatch, loop ropes over the apex and rappel down the monument.

The controversial urban planner who designed Washington, D.C., was buried in Maryland, and can presently be found in Virginia.

There's a 12-foot-tall replica of the Washington Monument hidden under a manhole nearby.

The 72-foot giant escaped confinement in a large patch of mulch only to be reburied in the sandy shores of the Potomac River.

This mysterious chalk figure of a horse has been recreated and restored for more than a century.

Also known as "Robin Hood's tree," this tree became a famed location along Hadrian's Wall before it was cut down in an act of vandalism.

Twice a day, the water of the Petitcodiac River flows upstream in a surfable wave.

These powerful, if squat, Canadian waterfalls flow in different directions depending on the time of day.

Iconic rock formations that allow for exploration during high or low tide.

Hunt for buried treasure in Nova Scotia.

The highest tides in the world come in and out here twice a day, allowing you to essentially walk along the ocean floor.

An interesting decoration on this historic site, this weathervane comes with as many legends as it does questions.

A mysterious stone embedded at the base of a historic Boston building.

This monument on Breed's Hill proves that one of the most famous battles of the Revolutionary War is misnamed.

The tomb of Increase Mather and his son Cotton, influential colonial ministers obsessed with the occult.

"Mock all and sundry things, but leave the saints alone."

Mrs. Mallard and her brood are a beloved fixture in Boston Public Garden.

This landmark cemetery in Boston was created more than 300 years ago.

The site of Paul Revere's historic two lantern warning.

Berthed at the Charlestown Navy Yard in Boston, "Old Ironsides" is the oldest commissioned warship still afloat.

The 5.5-mile ring of steel posts around the Capitol Building is one of the largest (and most uniform) of its kind in the world.

This statue of one of baseball’s greatest pitchers looks like something out of a sci-fi horror movie.