Nis; Serbia; Cele Kula (skull tower). The skull tower was made from the skulls of Serbian patriots defeated by Turks after a battle in 1809. It contained nearly 1000 skulls and was meant as a warning to help deter Serbian resistance and insurrection. After Nis was liberated; it was treated as a patriotic monument and war memorial; even though it was extremely dilapidated. Its walls are not extremely deteriorated; and few skulls remain. It is protected behind glass. Photo 2010.