Caerleon or Isca, being the home of the second Augustan Legion from 74 AD until late in the 4th century, needed substantial barracks to house up to 6000 soldiers. The stone foundations of these lie across the road from the Amphitheatre and beyond a field where you can take your responsible dog for a walk if you wish. They are the only such visible remains in Europe and are impressive in themselves as well as affording pleasure working out their layout, guessing (since there are few signs) what was what and imagining the life of the heavily armed and highly trained men who lived there. Probably this accommodation was rarely at full occupancy since the men might have been sent elsewhere in the country or be out on patrol. The structures above these foundations would have been made of wood.
There are pairs of long, narrow blocks 74 metres long facing each other and reflecting the division of the legion into double centuries (each consisting, confusingly, of 80 men). Each room was shared by 8 men with the centurion having a space up to 5 times larger that of the squaddy. Small anterooms for storage perhaps helped to keep the sleeping areas tidy and provided somewhere for the mattresses or palliasses to be put away in daytime. When some soldiers would be on night guard there was a little more room and one can imagine one man returning and prodding the next on duty with a weary and impatient foot. There may have been a veranda running down one side and an area for administration. The accommodation reflected the gulf between the commissioned centurion and common soldier: we know that in about 100 AD the former was paid 5000 denarii pa and the latter 300.
There is no mess hall and food would have been brought back from the small domed communal bread ovens, stamped with identifying marks. Corellius Audax and Sentius Paulinus performed this duty and, together with the baking itself, it must have been one of the more pleasant tasks. There were 2 types of loaf, one made with more refined flour for the officers. Meals might have consisted of pottage with scraps of meat and fish sauce, cheese with olive oil, beer and wine, some ingredients being scavenged from neighbouring farms and some imported. Soldiers at Caerleon drank Aminean wine washing down, possibly, beef, lamb, goat, deer, hare and the occasional treat of sucking pig.
Off duty the soldiers played games: counters and boards have been found elsewhere to prove this. Other occupations were the checking and cleaning of armour and equipment. There would have been time for worship of the several gods and military exercises in the amphitheatre as well as gory entertainment there. Such items as tweezers and nail cleaners for personal hygiene have been found and the baths were a central social facility. To keep the unruly Silures in their place, the soldiers had to be super-fit although their accommodation was centrally heated.
The latrines: a Roman's gotta go when a Roman's gotta go.
The remains of these are at the far end and they were communal with wooden seats over the drainage area. The men would have spread out their tunics to give themselves some privacy and cleansed themselves afterwards with a sponge on a stick (kept in a keyhole opening to the side) which was then rinsed in water running in a channel in front of them. This could be done without leaving the seats or lifting the garments. The cartoon shows a bucket for this purpose but I prefer the theory of fresh water! The whole process probably had a sociable aspect which we might now find strange.
Cleaning of the latrines would probably have been done by the men themselves and supervised: there were "ad cunus" (drain duties) and "ad stercus" (latrine duties). The disposal of the waste was less carefully supervised!
There are toilets nearby. Your visit to the barracks can be supplemented by looking at the amphitheatre, the fascinating baths and friendly museum, all of which are free. Caerleon is well served by buses which I have listed on my post about the amphitheatre. From Caerleon you can easily use the no 60 bus to visit Usk castle and nearby Medieval battle site as well as the memorial to Alfred Russel Wallace. You could stop off at Llangibby with its ancient well or go on to Raglan Castle or further to Monmouth with its connections to Henry V.