2 Samuel 18:18
Now Absalom in his lifetime had taken and reared up for himself a 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 unto this day, Absalom’s place.
During his lifetime Absalom erected for himself a costly pillar to serve as his own monument. He set that pillar up in the king's dale. That intended memorial stands in sharp contrast to what actually marked his end. In the wilderness a heap of stones became the only memorial over his grave. Those stones covered his dead body and stand as a token of everlasting reproach.