 This erosion cut away a large portion of the eastern part of the acropolis and revealed a vertical cross-section that measures high at its tallest point and long.Several buildings recorded in the 19th century were destroyed, plus an unknown amount of the acropolis that was eroded before it could be recorded.In order to avoid further destruction of the acropolis, the Carnegie Institution redirected the river to save the archaeological site, diverting it southwards in the 1930s; the dry former riverbed was finally filled in at the same time as consolidation of the cut in 1990s.