A camp built by the army (usually) by the side of a road whilst on the march. These could have been used for just a night or many times. Roman examples are usually regular rectangles or squares. Defences were provided by a ditch and rampart around the edge and at the gates. The entrances were defended by a clavicula or titulum. The sizes of marching camps has been used to estimate the size of the army on the march. Such Roman camps are hard to date due to sparse finds, general forms and style. It is possible to generally date some marching camps within the Roman period where they overlap one another, e.g. as at Chew Green, Northumberland. A good sequence of marching camps can be seen along Dere Street in Northumberland from north of Corbridge to the Scottish Border.