Albert Barnes Commentary 2 Samuel 21:12

"And David went and took the bones of Saul and the bones of Jonathan his son from the men of Jabesh-gilead, who had stolen them from the street of Beth-shan, where the Philistines had hanged them, in the day that the Philistines slew Saul in Gilboa;" — 2 Samuel 21:12 (ASV)

From the street of Beth-shan - This was the wide, open space just inside the gate of an ancient city, enclosed by the city wall (see the reference in the margin). Here, as it was the main public gathering place, the Philistines had fastened the bodies.