How Do We Know These Artifacts Are Designed if We Don't Know the Designer?

We don't know who made them. We don't know how they were made. We don't know what purpose they served. But we know they were intentionally made by mindful individuals. At least, Live Science never questions the design inference about strange stone structures in Middle Eastern deserts that are shaped like wheels, triangles, and long lines (see the photo gallery). Why is design the obvious inference?

There are hundreds of these structures. They extend over much of the Middle East: Syria, Jorda...