Guns that have been defending San Francisco since 1904.

A historic hotel that made a cameo in Hitchcock's classic film has no intention of letting guests forget its fame.

This massive collection of British military artifacts includes the heartbreaking personal letters of the men in the trenches of WWI.

These remote Florida islands have a history of sea turtles and sunken treasures, and one of the world's largest coastal brick fortresses.

The boulder on which Alexander Hamilton laid his head as he died can still be visited on the New Jersey coast.

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

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

A dramatic, 360-degree recreation of Pickett's Charge in the Civil War.

The popularity of Sherlock Holmes led to the creation of his fictional address, turning the orderly London street numbers askew.

This luxury shopping lane has been protected by its own tiny police force for over a century.

A historic presidential getaway on the continental United States' southernmost island.

A building so large that it has its own weather.

A monument celebrating the idea of reaching inaccessible places.

A Roman-style column in Oregon hides a spiral staircase inside.

100-year-old shipwreck you can walk up to at low tide.

A massive sea stack famous for its appearance in The Goonies.

Lie in a hammock where George Washington stood.

Possibly the world's largest coin stands just outside of a Canadian science center.

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

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

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

The first American department store, and home to the largest operating musical instrument in the world.

Ride the subways of yesteryear.

An 18th-century Spanish watchtower made entirely of seashell and concrete.