Was there an actual purpose to this strange metal megaphone attached to a rock in the middle of nowhere in the Mojave Desert? Maybe it was a weapon? A drum? An antenna? Or is it just a prank that some joker took the time to set up and wait for someone to notice? No one seems to be exactly sure.

This large, megaphone-shaped mystery object is bolted to two rocks on top of a 100-foot hill along a remote strip of desert between the towns of Baker and Ludlow. Some say it’s shaped like a venturi — though they normally are hour-glass shaped — and its shape is more like a rocket nozzle. It’s about 8 feet long, made from thick strips of iron welded together. Many travelers and historians alike have searched for an explanation of how it got there, and for what reason. But while theories abound, the answer remains elusive.

One theory suggests that the megaphone was used to amplify a siren that alerted locals when the U.S. Army was conducting secret chemical or gas testing in the area. Another wildly different theory posits that visitors would hike out there and stretch skin over the ends of the object to play it like a drum. Whatever the origins, catching a glimpse of this mysterious “megaphone” atop the rocks is a strange and unexpected sight indeed.