Archeological excavations began in 1985 led by Lawrence Stager of Harvard University; the site is about 150 acres with about 50 feet of accumulated rubble from Canaanite, Philistine, Phoenician, Hellenic, Roman, Byzantine, Islamic, and Crusader occupation. The city was originally built on a sandstone outcropping and has a good underground water supply. It was relatively large as an ancient city with as many as 15,000 people living inside walls a mile and a half long, 50 foot high and 150 feet thick.
Excavation is just beginning, but interesting discoveries have already been made, especially about the Philistines. During the Crusades, Ashkelon (which was known to the Crusaders as Ascalon) was an important fortress for defending the Kingdom of Jerusalem from Egyptian attacks. Although the Egyptians were defeated there by the Crusaders in 1099, the city itself was not taken until 1153. Ashkelon was later destroyed by Saladin as a defensive measure during the Third Crusade. It was rebuilt but the site was abandoned during the 1300s.