Most of these constructions seem to be smaller than Göbekli Tepe, and their placement evenly between contemporaneous settlements indicates that they were local social-ritual gathering places, with Göbekli Tepe perhaps as a regional centre. So far none of the smaller sites are as old as the lowest Level III of Göbekli Tepe, but are contemporary with the younger Level II (mostly rectangular buildings, though Harbetsuvan is circular). This could indicate that this type of architecture and associated activities originated at Göbekli Tepe, and then spread to other sites.