Researchers discovered 30 hidden bayonets from the times of American Revolutionary War (1775–1783) near Valley Forge National Park in South-east Pennsylvania, USA.

The area where the discovery was made is a private property outside the park, but in 19th century it was part of the encampment where the Continental Army famously spent a hard winter from December 1777 to June 1778. Researchers using metal detectors first located a nine-pound cannonball hidden underneath a walking path, and a cache of 30 bayonets, stacked together. The bayonets were of various makes and manufactures, reflecting the army’s state. The bayonets also show evidence of modification, as if someone had tried to fit them to muskets they weren’t intended for. Another find was a musket ball that had been turned into a die with Roman numerals on its faces, and a particularly rare U.S.A. uniform button featuring stylized lettering and the year 1777.

(after Atlas Obscura, Glen Gunther, Jesse West-Rosenthal & Battlefield Restoration & Archaeological Volunteer Organization)