During his lifetime, Absalom had set up for himself a pillar in the King’s Valley, for he had said, “I have no son to preserve the memory of my name.” So he gave the pillar his name, and to this day it is called Absalom’s Monument.
Jewish Publication Society of America Version (JPS1917) - 2 Samuel 18:18 >Now Absalom in his life-time had taken and reared up for himself the pillar, which is in the king's dale; for he said: 'I have no son to keep my name in remembrance'; and he called the pillar after his own name; and it is called Absalom's monument unto this day.