A hidden three-foot-wide house separates these two regal churches.

For decades, Puerta del Sol has been illuminated by a giant, guitar-wielding bottle of sherry.

Inaugurated three times, this tower offers some of the best views of Madrid.

More than 7,000 gallons of water pour over these cascading red quartzite waterfalls every second.

America's first National Historic Landmark is a 100-foot tall obelisk and gravesite dedicated to the only casualty of the Lewis & Clark Expedition.

Dedicated to nine marines from Massachusetts who perished during the Beirut bombings.

This "life-size" depiction of Mickey Mouse as a half-lobster is both whimsical and a bit creepy, standing guard over the Boston waterfront.

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

The first bell ever cast in Boston was cast by Paul Revere...and sounded terrible.

A former waterfront market is now in the center of town due to some interesting Boston engineering.

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

Historic Hull Street was actually the first street with a proper name in the Boston area.

The site where Charles Dickens gave his first public reading of "A Christmas Carol" in the US.

This historic patch of real estate offers a glimpse of colonial Boston.

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.

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 American Revolution was galvanized into serious action due to the tragic clash with British soldiers that occurred at this location.

The site of one of the strangest disasters in history—a wave of deadly molasses traveling at 35 mph.

One of the oldest used bookstores in the U.S. has been selling antiquarian treasures since 1825.

The first public building in Savannah to offer air conditioning was a luxurious cinema that still operates today.

One of Savannah's oldest and most haunted cemeteries, featuring graves desecrated by Sherman's Union Army.