RAISING THE SIEGE FORT. Silva’s first operational order was to construct a circumvallation wall around the site to prevent the rebels escaping. More than 5 feet wide and 10 feet high, the wall was composed of rough stone blocks with a rubble core. This section of the wall has been reconstructed and is located near Wadi Sebbe, a critical area where the Jews might have attempted a sortie. The circumvallation wall was built even over difficult terrain where escape would have been impossible, further demonstrating to the rebels Silva’s determination to bring an end to their resistance.