There are two major Roman sites just ten miles apart in south Wales, both amongst the best remains from this period in Britain; Caerwent Roman Town near Chepstow and Caerleon Roman Fortress just north of Newport. This latter location, one of only three permanent Roman legionary fortresses in the UK (the others were at Deva, Chester and Ebor, York), was established, as Isca Augusta, around 74 AD during the latter stages of the Roman invasion of Wales, and was occupied for around the next 300 years, though major use declined after 300 AD or thereabouts.
The main part of the fortress was a walled enclosure covering one square mile, crossed by a regular array of streets, and mostly containing barrack blocks, together with administration buildings, storage facilities, a hospital and a bath house. Just outside the wall section was, unusually for England, a great amphitheatre, and recent discoveries have revealed the presence of other large buildings further away from the centre.
Today, about three quarters of the fortress site is buried beneath the village of Caerleon, and there is no visible trace of most of the structures, however three major relics can be seen. The best is the amphitheatre, which has buttressed walls up to ten feet high, around the interior and parts of the exterior, and is entered via eight symmetrically placed entrances; altogether one of the best preserved amphitheatres in northern Europe. The other sites are the remains of a bath house, including a frigidarium, all now contained within a modern building for protection, and the foundations of four barracks blocks. Only one of these is authentic, however; the other three were re-created from the footprint of the original walls, as revealed by surveys. Also of interest is a 1000 foot long section of the fortress walls, at the south corner of the site, bordering the amphitheatre. These four locations are within a few minute's walk of each other, and there is no charge to visit them.
Caerleon is 3 miles northwest of Newport, on the far side of the River Usk. A free parking area for visitors to the Roman sites is located along Broadway, a dead-end road off High Street, leading to the local rugby club. The surroundings are grassy fields, extending south towards the inside of a big bend along the river, and covering the southernmost quarter of the fortress site.
The most spectacular part of the fortress, the amphitheatre, is located in a field on the south side of the road. Most was buried until the early 20th century when the interior was excavated, revealing the inner walls and the eight entrances, some larger and more complex than others, and some partly built using red bricks, which make a pleasing colour contrast to the otherwise dark grey of most of the masonry. The structure dates from about 200 AD, after two earlier amphitheatres on the same site where destroyed. The walls would have supported rows of wooden seating, rising quite high above the floor, and accommodating up to 6,000 spectators. The surviving section of the city wall is just beyond, curving round a corner and continuing a little way northeast; maximum height is about 12 feet.
The barracks are 600 feet north of the road, in an area known as Prysg Field, reached by a path that parallels the course of the fortress walls, though this section has long since disappeared. The four blocks, out of a total of over 70 in the whole fort, are at the west corner of the site, next to a few other low wall remnants, from two towers and several horseshoe-shaped ovens. The original block is the westernmost, though the other three look almost identical. All have the same design, slightly wider at one end, where some larger rooms were situated, used by officers (centurions), then narrower for the remainder, containing smaller rooms for the regular legionaries. These are apparently the only surviving Roman barracks in Europe.
The bath house, near the centre of the fortress, is now contained within a building on the east side of High Street, adjacent to a pay car park though just a short walk from the free area along Broadway. The Roman remains are a little below today's ground level, and are viewed from a few feet above via walkways. The two main sections are the (hot) bath, and the frigidarium, a cold water pool. The main bath is merely an empty rectangle, illuminated by moving blue light to create a rippling water effect, but the frigidarium is more interesting, containing various enclosures and walls, and other features such as a drain cover and blocks from an underfloor heating system.