Telassar or Thelasar
(Assyrian hill) is mentioned in 2 Kings 19:12 and in Isaiah 37:12. As a city inhabited by “the children of Eden”—which had been conquered and was held in the time of Sennacherib, by the Assyrians. it must have been in western Mesopotamia, in the neighborhood of Harran and Orfa.
Smith's Bible Names Dictionary (1866)