The Norman castle at Usk sits on a low hill just north of the town centre, 800 feet from the River Usk, bordered by wooded slopes on all sides, giving the place a secluded, scenic, rural aspect despite being close to a busy main road, the A472. Unlike most ancient south Wales castles the place is privately owned and part is still inhabited, though the public may visit most days of the year, after payment of the suggested £2 donation.
The family who own Usk Castle live in buildings along the south side, at the edge of the outer ward which adjoins the slightly higher inner ward, a 240 foot-long enclosure ringed by curtain walls that incorporate several buildings, principally the keep, chapel, great hall and three towers. Most of these survive at or near their original height, and limited restorations have helped preserve some sections. The ward is centred on a flat lawn, often used as an outdoor event venue, while all around are flower beds, herb gardens, bushes and trees, adding to the pretty, peaceful surroundings. The walls are lowest to the southwest, allowing grand views across town towards distant hills.
The hill above what would become the town of Usk had been used for defensive purposes since Roman times, many centuries before Usk Castle was established, by the Normans around 1120. The adjacent town was founded about 50 years later. The first overlord of the castle was probably Richard FitzGilbert de Clare; soon after his death in 1136 the fortification was captured by the Welsh, but soon retaken and then subject to several changes of ownership over the next three centuries, to other de Clares and also the Marshall, Mortimer and Despenser families, before passing to the Dukes of Lancaster in the early 15th century, following the end of the rebellion of Owain Glyndwr, this the last major episode in the conflict between Wales and England. The castle was later abandoned and gradually became ruinous until part was redeveloped as a residence at the end of the 17th century.
Free parking is available along a short side road just east of the castle, in a clearing in the woods. The approach is along a driveway to the 17th century residence (Castle House), which incorporates part of the later gatehouse, from the 14th century. The surviving part of the outer ward is just beyond, now a private garden, with fragments of curtain walls along the edge, and the dovecote tower at the south corner, a decorative rather than defensive structure, so named since it was in more recent times converted into a nesting place for doves. This tower is also not open to the public. The outer ward once extended northeastwards, though this region now is overgrown woodland, with no trace of the original enclosing wall.
Visitors proceed along a short path, past the information kiosk where donations are paid, up a flight of steps and through a doorway in the east wall of the inner ward, the main part of the castle. The most imposing structure here, just south of the entrance, is the square, three-storey keep, formerly the gatehouse, which has doorways on the first floor and variously-shaped windows above, plus a fireplace. The keep was built by Richard de Clare (nephew of Richard FitzGilbert) around 1170. Other major features, moving clockwise, are the mostly ruined southwest tower, the circular, four story garrison tower built in 1209, once accessed by a spiral staircase and still linked by wall walk to the end of the great hall (1314), then the chapel, and the late 13th century north tower, also known as the treasure tower.