Many mysteries surround these objects questioning whether they are cannonballs at all.

Dedicated to the five postal workers who died aboard the doomed ocean liner, this plaque was made from a spare propeller from the Titanic.

This modest site memorializes a World War II mission described without hyperbole as “the greatest raid of all.”

This observation tower is one of two of its kind that still exist in the United Kingdom.

Constructed for defense, this fort oversaw the dress rehearsal for one of the largest invasions in history.

In 1977, an eccentric book lover formed a micronation for book lovers.

The wreck of a World War II cargo ship has become an unintentional time capsule at the bottom of the Red Sea.

This vessel is the final ocean-going paddle steamer in the world.

This mangled and twisted wreckage left by the side of a Mexican road was no accident, but a planned crash in the name of science and safety.

Some of the last remaining relics of one of World War II's most important invasions.

Three tiny islands in a Portsmouth pond are at the center of disputed land claims from a number of competing micronations.

One of the country's largest diving schools set in a picturesque nature reserve.

After protestors toppled a statue of a 17th-century slave trader, the pedestal where it once stood remains unoccupied.

After a long career, a disastrous sinking, and a half-successful salvage, this Naval vessel-turned-artificial reef ended up exactly where she was supposed to—with a little help from nature.

Six miles off the coast of Key West, a former military transport ship is now one of the largest artificial reefs in the world.

Built as part of a "sludge fleet" that transported sewage, this historic steamship now mostly moves people.

The real clothing store that inspired a fictional spy organization's front.

A ferry has operated across the River Hamble for around 500 years, but its distinctive bubblegum pink is a more recent addition.

In the 1970s, the citizens of several small villages came together to stop their homes from being destroyed for a new airport.

Planes, helicopters, and a shipwreck are underwater in this former limestone quarry.

This concrete monster of a wreck lies in the mouth of Langstone Harbour as a monument to the incredible history of D-Day.