http://agathe.gr/guide/panathenaic_way.html
Panathenaic Way Numerous roads led in and out of the Agora square. By far the most important, however, was the broad street known as the Dromos or Panathenaic Way, the principal thoroughfare of the city ... The line of the street was defined in the Hellenistic and Roman periods by successive open stone gutters along its south side (Fig.5). Basins in the line of the channel caught sediment and helped keep the channel clean; those off to the side presumably provided water for draft animals. ... Limestone channel with water basins along the Panathenaic Way.