It's Too Cold Outside, Centurion

Join the Roman army, you'll get regular pay, regular food, toilets with water flushing, and indoor training facilities. Because it was essential for soldiers to have "unceasing drill in wet and windy weather," as the military writer Vegetius said.

Example one: Birdoswald / Hadrian's Wall. The guys had a basilica exercitatoria, a drill hall measuring 16 x 42.7 metres.

Birdoswald, view from the south gate over the granaries to the exercise hall
and the 17th century farm house
Unfortunatley, not much is left. The foundations directly in front of the farm house (beyond the remains of the granaries) are the south-west part of the drill hall - the other part is today covered by the house. The headquarters (principia) had been beyond the trees to the left, but not much remains of these, either.

From the foundations of the drill hall it can be deduced that the roof was a double arcade supportend by a series of columns flanking a broad nave. Light came from windows above the arcade. The style was a typical feature of Roman public buildings and later used in the triple naved Romanesque basilicas all over Christian Europe.

My guidebook has a drawing of auxiliary soldiers training with wooden swords and wicker shields in the basilica exercitatoria. In the foreground, a centurion is barking commands; he looks rather grim. Some poor sods are in for an extra session.

The drill hall remained unaltered during the entire period of Roman occupation of Birdoswald (Banna) which shows its importance.

Saalburg, interior of the reconstructed exercise hall (view to a side door)
The next example comes from the Saalburg at the German Limes. Here the exercise hall was not a separate entity but part of the principia.

This one measures 11.5 x 38.5 metres and is constructed as simple hall without side naves. The hall is situated directly on the axis of the via praetoria and its crossing the ways leading to the side gates.

Part of the floor has been found during excavations, as well as proof that wooden canopies protected the doors on the outside.

The position of the hall allows us to assume that it was not only used for training but also as meeting place for the entire cohort on formal occasions like the annual oath to the Emperor.

Saalburg, basilica exercitatoria, door leading to the yard of the principia
The troops stationed in the border forts were not legionaries - those had their base camps futher off in Eboracum (York) or Moguntiacum (Mainz) - but auxiliaries recruited from all over the Empire. As mentioned before, the garrison in the Saalburg was the second Raetian cohors equitata since 135 AD. The garrisons in Birdoswald varied; it included the First Aelia Dacorum milliaria, a 1000 man strong double cohort from the Danube that moved in shortly after Septimius Severus established major restructuring of the Wall defenses in the early 3rd century.