This is a crossroads in Priene (Turkey), and what you see is a stone water division box for directing fresh water to its destination. It is not Roman, but Greek. What you cannot see on the picture was the amount of people surrounding me when I took this picture. There are conferences about urban water supply in the ancient world, and they tend to be in nice places. This was the 2004 Cura Aquarum Conference, which took place in Ephesos.
Miko Flohr, 16/03/2011