Aqueduct of Saint Lazar (of Emerita Augusta), at Merida, Badajoz.
It is one of the three conducts that gave Emerita Augusta water. As this aqueduct had to cross depression of Albarregas river, many archs were built in to support conductions. Only three great pillars with two of its union archs: the lower in the structure, are preserved from the whole. At 16th century a new aqueduct was built using many ashlars from the Roman one: so, this was almost ruined.
Three pillars remaining have a different plan: they all have buttress to make stronger the general structure.
First floor have archs of 11 voussoirs with a slightly outstanding key. Pillars, with a rectangular plan, are made of exagerately padded ashlars dispossed at 9 files. To end this first whole of archs, there is a moulded cornice tangent to the top of the archs. All this whole forms the aqueduct's basement.
Second series of archs is built with flat ashlars more or less irregular. Parallel files of bricks can be sen periodically inserted. Number of files is the same for both: four files of ashlars; four of bricks. Pillars have cross form and not rectangular one, as those from first floor. They have a moulded cornice before the beginning of the archs. These are made of bricks and do not directly support conduction of water.
It should have been built at two different moments, as can be seen from the different way of constructing between lower and superior -middle of 1st and 2nd centuries- series of archs. Other scholars think that it is earlier: from Augustus age.