In 1718, the infamous pirate captain Blackbeard ran his ship the Queen Anne's Revenge aground at Beaufort Inlet following his lengthy blockade of Charleston Harbour. The exact reasoning behind the grounding are disputed, with some suggesting that he did so deliberately to help his crew escape from capture. By abandoning his ship, the captain - who was killed in a vicious battle with Lieutenant Robert Maynard's crew mere months after the Beaufort Inlet incident - had inadvertently created a site of great historical significance.

In 1996, a search team discovered the site of a shipwreck now widely believed to be that of the Queen Anne's Revenge. Since then, teams have managed to recover artifacts ranging from pottery fragments to huge 18th century bells and anchors.

On Monday, researchers managed to secure another five cannons from the shipwreck - four weighing 2,000 pounds, and a separate 3,000 pound cannon. They're believed to have been capable of firing cannonballs up to distances of 2 miles. Altogether, 20 cannons have now been pulled from the wreck.

In a statement released to Popular Science, recovery project director Billy Ray Morris explains "we think the largest of the four cannons may be of Swedish origin since the only other recovered gun this size was made in Sweden. We also hope to recover two large concretions each the size of a twin bed. They may contain barrel hoops, cannon balls and other treasures."

The North Carolina Department of Cultural Resources has commissioned an interactive map showing the various artifacts that have been recovered from the shipwreck. You can check it out by clicking here.