The arrangements made in ancient cities for the management and use of water varied over the extent of the Greek world, depending on local topography and geology. They also varied by time period. In the absence of detailed whole-site studies, we can no more than suggest some of those differences. Our method will be to examine one early city and one late, looking for similarities and differences. The chosen examples share the useful (for us) feature of having been destroyed, so that their ruins preserve a set of arrangements not diluted by later habitation. The examples chosen are Olynthos in northeast Greece, destroyed at the end of the fourth century B.C., and Pompeii near Naples in southern Italy, destroyed in A.D. 79. A description of each will point out features that are typical for that time period, and we will conclude with a direct comparison of the two water management systems. Olynthos (Fig. 13.1) is located in northeastern Greece, at the base of the left peninsula of the set of three which also includes Mount Athos. Geological maps of the area (Institute of Geology and Mineral Exploration, “Geology of Greece” series (1:50,000), Athens, Greece, ca. 1984) show that a large limestone massif terminates just to the north of the site, and could be tapped for its karst waters. Indeed, a pipeline was found coming southward for five miles (D.M. Robinson, 1935, 219 ff and fig. 12; Robinson and Clement, 1938), from the springs near Polygyros and from northeast of the church of Hagios Nicolas. More traces of the line were observed in the plain. In Volume II of the Olynthos excavation reports (Robinson, 1930, 12), the line is thought to be sixth century because of some fragments of black-figure vases found with it in the dig, yet in Volume XII this aqueduct was declared fifth or fourth century because of its beautifully cemented joints with mortar of pure lime with a little silica (Robinson, 1946, 107). The line is described as having pipes about 3 inches thick (.45 centimeters), and therefore is probably a pressure pipe.