But there was a strong tower within the city, and thither fled all the men and women, and all they of the city, and shut it to them, and gat them up to the top of the tower. (Judges 9:51)
Towers like this have been found in Palestine with stone walls as much as 14 ft. thick. There were floors or stories within the tower with a platform on top from which to defend it. Into this last formidable citadel the citizens of Thebez fled after Abimelech had broken through their city walls. The frequent mention of towers reflects the unsettled state of the country.