In this photo of the tulmus you can see things a little more clearly. Notice the camp's main ramparts and the wicker work wall and the all important arrangement of the other gates.

Behind the tulmus and gateways were the important parts of the camp itself. The homes of the men. Each typical legion had ten cohorts, each of three maniples. Each maniple was further divided into centuries (sixty to one hundred men) and then squads called conterbernuims (six to ten men each). Each squad shared a single tent. I have obviously scaled things down. In Cicero's camp the tents were actually replaced by thatched houses equal in size to the typical marching tent which would not have been very good in the winter months. I chose to show tents rather than wood buildings with thatching. It is possile that Cicero's men may have simply covered the tents with thatching.

Notice too the uniformity of things. These include the road ways inside the camp as well as the layout of the tents and towers. Also take note of the back of the rampart and walls. See how they are something like gentle hills? This made it easy for the men to mount the wall's ramparts.

The walls would also be defended by all kinds of balsita or artillery. The main weapon used from atop the wall by the men would be javelins and the heavier pilae or heavy throwing weapons for which the Romans were famous. The height of the walls and towers would add range to the javelins (about twelve feet high). Auxilia or allied and mercenary units of archers and slingers would also man the walls with the Romans.