Just when you think a historic site has given up all of its secrets, new wonders sometimes rise to the surface, as was the case at Michigan’s Fort Michilimackinac, where researchers recently found a brass lock dating back to the Revolutionary War.

Revolutionary War-era lock unearthed at Fort Michilimackinac https://t.co/aGsHURjPuZ — Muskegon Chronicle (@MuskegonChron) June 22, 2017

According to Muskegon Chronicle, the centuries-old lock was discovered during the excavation of a an old fur trader’s house. Unearthed in the root cellar, the ornately-styled lock is made of brass, and is thought to have come from a chest or trunk circa 1760-1770. The artifact measures almost three inches tall, significant compared to the tiny beads and other bits of history that is usually found at the site.

Once the lock is cleaned, it will be put on display, proving that even after some places become historic tourist destinations, they can still provide some surprises.