Someone left these marks in the sand. We had to find out who. Subscribe and turn on notifications 🔔 so you don't miss any videos: http://goo.gl/0bsAjO Deep in the Sahara, far from any towns, roads, or other signs of life, is a row of markings in the sand. There are dozens of them stretching for miles in a straight line in central Algeria, each consisting of a central point surrounded by a circle of 12 nodes, like numbers on a clock. And when we started making this video, no one seemed to know what they were. We first saw the circles back in September 2021, after finding a Reddit post on r/WhatIsThis with coordinates asking what the circles could be. With just two upvotes and two commenters, it wasn’t exactly a lively discussion. But seeing the circles themselves on Google Earth was fascinating: They were eerily perfect in their shape and regularity, but so deeply isolated in the desert. We were hooked on finding an answer. So we decided to make a video out of trying to solve the mystery, no matter where it took us. We documented every step of the process — from Zoom calls and web browser screen recordings to vlogs and field shoots — to show the reporting process from the inside out. And when we maxed out what we could learn on the internet, we handed over this story to a team in Algeria to take it all the way. Resources: Check out the circles for yourself: https://www.google.com/maps/@27.270129,4.3221894,251m/data=!3m1!1e3?entry=yt Read Will K’s original post: https://www.reddit.com/r/Whatisthis/comments/nv4ysr/ive_just_discovered_unexplained_and_undocumented/ Here’s the 1885 document that Melissa found: https://www.journals.uchicago.edu/doi/pdf/10.2307/495986 Read Dale Lightfoot on the sustainability of qanats: https://link.springer.com/article/10.1007/s12685-017-0200-7 My interview with Marta Musso didn’t make the final cut, but you can check out her work on the history of the hydrocarbon industry and Algerian decolonization: https://www.jstor.org/stable/j.ctt1mtz521.8?seq=1 I also spoke to Roberto Cantoni, who wrote a great book that covers the same history: https://www.taylorfrancis.com/chapters/mono/10.4324/9781315531533-4/oil-diplomacy-wartime-algeria-roberto-cantoni Make sure you never miss behind the scenes content in the Vox Video newsletter, sign up here: http://vox.com/video-newsletter Vox.com is a news website that helps you cut through the noise and understand what's really driving the events in the headlines. Check out http://www.vox.com/ Support Vox's reporting with a one-time or recurring contribution: http://vox.com/contribute-now Shop the Vox merch store: http://vox.com/store Watch our full video catalog: http://goo.gl/IZONyE Follow Vox on Facebook: http://facebook.com/vox Follow Vox on Twitter: http://twitter.com/voxdotcom Follow Vox on TikTok: http://tiktok.com/@voxdotcom