2005
http://creativecommons.org/licenses/by-nc-sa/ , info:eu-repo/semantics/OpenAccess
Mukhammed A. Mamedov et al., « The Parthian fortresses of Nisa, Turkmenistan : nomination of the ancient parthian sites of Nisa for inclusion on the UNESCO World Heritage list by the Government of Turkmenistan », HAL-SHS : architecture, ID : 10670/1.f5u943
Old Nisa is a 14-hectare tell surrounded by a high defensive earth rampart with more than 40 rectangular towers. Its contours take the shape of an irregular pentagon with the corners flanked by powerful bastions.The entire site was built on a natural hill, the top of which had been levelled up and flattened with layers of earth (pakhsa). The number and location of the gates have not been precisely determined yet. The most probable location of the main and, perhaps the only entrance, was at the centre of the western part of the surrounding wall.