Open all year during reasonable daylight hours; no admission charge and unstaffed. Cadw often restricts access to protect the ground in extreme weather; check with Caerleon Roman Baths (03000 252239) if visiting in poor weather. The Roman Baths nearby charge admission; the barracks and amphitheatre do not.
Terrain level 2, easy: a flat path beside the school to a grassed field that is uneven in places and can be slippery and muddy, with low wall remains throughout that are a trip hazard for anyone using mobility aids. No toilets at the site; public toilets at the Broadway car park and an accessible toilet in the free National Roman Legion Museum. Drones are not permitted.
Dogs: Cadw: 'Dogs welcome. Dogs on short leads welcome to access ground floor levels of the site.' An open-air, ground-level site, so the ground-floor wording restricts nothing; the access guide welcomes dogs on leads in the outdoor areas including the barracks. The amphitheatre a few minutes' walk away carries the same short-lead welcome; the National Cycle Network route past the site states no dog rule.
Photo: The stone footings of a barrack block at Prysg Field, Caerleon, its rows of paired rooms set in mown grass below the rampart bank. Otter, CC BY-SA 4.0. Source: https://commons.wikimedia.org/wiki/File:Caerleon_Roman_Fortress_20171016_Prysg_Field_Barracks.jpg. Licence: https://creativecommons.org/licenses/by-sa/4.0. Resized and cropped for display; derivatives retain the source licence.