A long, long time ago, in a country far away, I worked on an archaeological excavation at a site called Tel Rehov.
Toiling in the dirt is more than fun. And we found our fair share of buried treasure--Please note that in the context of an excavation, a broken pottery vessel is, in fact, buried treasure. It's a connection to the ways of the ancients, so regardless of how pretty (or dirty) an artifact is, it's bagged and tagged and studied.
Now, structures that are preserved in their original location, so they can be examined in the context of the space they filled or defined. Structures, AKA features in archaeological speak, can be anything from walls to hearths. Generally speaking, an experienced archaeologist can tell you what something is just by looking at it. (Identifying walls may seem like an easy job, but I would encourage you to try it sometime before making any snide remarks about needing experience.)
That being said, it was a bit odd to come across these cylindrical features during excavations. Initially, the lead archaeologists on the site had no idea. Who would have guessed they would have found beehives? Check out the AP story.