Skull tower in Nis, Serbia

This is second miniature postcard from Niš, Serbia.  Postcard is 3x2cm and skulls are 3x4mm.
This Skull tower (or Ćele kula in serbian)was fought in 1809. during the first Serbian uprising. Serbian revolutionaries led by commander Stevan Sindjelić were attacked by Turkish forces on Čegar near Niš. Rather than have him and his men be caught by the Turks Sindjelić fired his pistol into a powder warehouse, killing himself and all Serbian rebels and Turkish soldiers in the vicinity. After that, Turkish commander of Niš ordered that a tower be made from the skulls of the killed Serbian revolutionaries. Skull Tower contained 952 Serbian skulls.
Today they are only 53 skulls left.