INVESTIGATIONS ALONG THE WESTERN AQUEDUCT OF NICOPOLIS AD ISTRUM (Ivan Tsarov – tsarov@abv.bg) The Dichin-West Site. The specus known from 2003 was investigated in two new areas – A and L. The aim was to clarify the existence of two duplicated terracotta pipelines. Fragments of terracotta pipes, two of them connected by a socket, were found in area A. The pipes were dismantled and only some terracotta fragments were left on the site. Later, some time after dismantling, the ditch was gradually filled with debris from the destroyed pipelines. The existence of a ledge testifies that the specus rose above the surrounding terrain in antiquity. Because of the erosion of the riverbank, the place where the arches joined the specus has been destroyed, and the beginning of the pipes is missing. Part of the southern side of the specus was excavated in area L. The Rositsa River Site. In 2003, five piers from the arches of the aqueduct were discovered within the riverbed. In 2004, Pier No. 5 (3.65 by 3.05 m), partly lying on the riverbank, was excavated. The other piers lie in the river, almost entirely covered by river deposits. It was possible to measure only Pier No. 4 (3.8 by 2.8 m). Piers Nos. 4 and 5 are not aligned and obviously, the arches of the aqueduct made a turn of 34 degrees there. In antiquity, the channel, currently silted up, was the main riverbed. Piers constructed of monumental limestone blocks were built within the ancient riverbed and alongside it. As far as Piers Nos. 1 – 5 are concerned, in antiquity they were built on dry land. A fragment of a stone channel, identical to others known from different parts of the aqueduct, was found close to Pier No. 5.