sentences:  It is said that of the walled city a deep trench was also dug to control un authorized entry.The trench was crossed by a movable wooden bridge which used to be lifted at night by the guards of the gates and Garrison closed at night.According to some historians there was a tunnel inside the walled city which connected Hund Garrison with Attock fort so that both Garrisons can reinforce each other in case of attack and used the tunnel as a withdrawal route in case a Garrison fell into enemy hands.