sentences:  There is archaeological evidence for widespread burning of fortifications, but it is disputed whether this represents fortifications falling to attack or part of the normal process of the Roman military to destroy their own fortified camps on abandonment so as not to furnish the enemy with a fortified base at their expense.These northern fortifications are sometimes styled the "Limes Britannicus".The average garrison of the wall fortifications is thought to have been around 10,000 men.