Remember those mini locks we used when we were kids to keep our diaries safe? It seems like the ancient Romans may have also delighted in such miniature objects. A metal detectorist in Germany has unearthed a tiny ancient Roman golden lock. The 1,600-year-old artifact is likely the first discovery of its kind in Europe, and sheds light on the extraordinary blacksmithing and locksmithing skills present in ancient Roman provinces. Hailing from the third or fourth century CE, the miniature lock is 0.43 by 0.47 inches (1.1 by 1.2 centimeters). Itssmaller than the one-euro coin but so much more valuable, said Georg Lunemann, director of the Westphalia-Lippe Regional Association (LWL), in the associations January 28 statement describing the discovery. I am thrilled that we can come up with such high-profile finds here in Westphalia, he added, a region in northwestern Germany where the detectorist found the lock. The discovery of the lock. LWL / C. Fried Based on its shape, construction, and style, archaeologists at LWL immediately identified it as a Roman lock from the third or fourth century CE, produced in one of the imperial provinces. In fact, it was identical to a regular ancient Roman lock in everything but its size. Although the detectorist, Constantin Fried, found the artifact without its chain and key, it likely resembled a bike lock and could have secured a chest or box. A single chain link survived, and is still visible inside the lock. I could hardly believe it myself when I held the find in my hand, said Fried. Hed found the artifact in a field in 2023. Because such Roman locks are usually much larger and consist of iron or even bronze parts. The lock is made of two cylindrical metal sheets, one inside the other, held together by two circular ends and secured by three rivets. The external sheet is intricately carved.Director of LWL archaeology Michael Rind suggests that a local high-class individual may have brought the lock back home to Westphalia as a souvenir or gift after completing his Roman military service. Even 1,600 years ago, locals likely saw it as spectacularand may have even worn it as jewelry. Was it a one-off production or have similar precious miniatures just not been found yet? These and other questions will keep us busy for some time, Rind added.But could it really function like a true lock, or was it just a beautiful curiosity? To answer that, the researchers examined the objects interior. When traditional X-rays failed to penetrate the locks dense gold exterior, the team turned to a less common archaeological tool: 3D neutron computed tomography (CT), a technique that images the three-dimensional structure of a sample using neutrons. The processed neutron CT images. They reveal a frame with spring (red), bolt (blue), broken bolt guide (yellow), pin for the key (green), base plate (purple) and a chain end link (orange). Paul Scherrer Institute/Villigen (Switzerland)/David Mannes; Montage: LWL/Corinna Hildebrand The neutron CT images confirmed that, despite its size, the artifact did have a functioning iron locking mechanism, revealing a frame with spring, a bolt, a broken bolt guide, a pin for the key, a base plate, and the chain end link. While largely complete, [the mechanism] was damaged, because someone had obviously poked around in the lock at the time, probably to break it open or to fix a blockage, Fried explained. Despite the damage, we were able to reconstruct the function of the mechanism and the lost key quite well, Rind said. With the end link of the chain still in place, it was also possible to reconstruct a link chain for the lock that must have had at least six [links] for the lock to function.The large reconstruction of the closed lock with the chain and key, by LWL /Eugen Msch. LWL /Stefan Brentfhrer An LWL-Archaeology restorer then crafted a functional replica of the lock, complete with a chain and key. The replica, four times larger than the original artifact, highlights the high level of skill in provincial Roman artistic blacksmithing and locksmithing, explained Barbara Rschoff-Parzinger, head of the LWLs cultural department. That doesnt mean ancient Romans couldnt have worn the functioning lock as jewelry anyway. Perhaps the true revelation is that our obsession with chunky chain necklaces and lock charms began 1,600 years ago.