[2] Originally covering 4.6 acres (1.9 ha), the surviving remains of the square castle include residential blocks, together with a section of parapet wall forming an L-shape to the southeast.

[4] A timber castle existed in Swansea in 1116, when it was recorded as being attacked by Welsh forces who destroyed the outer defences.

[4] The original castle seems to have been a sub-rectangular/oval enclosure overlooking the River Tawe on the east, surrounded on the north, west and south sides by a larger sub-rectangular outer bailey.

[5] The motte (or ring work) was 52 metres (171 ft) in diameter (only second in size to Cardiff Castle) and survived to the early 20th century.

[4] After various other unsuccessful attacks the castle fell in 1217 but was restored to the English in 1220 as part of the settlement between Llywelyn ap Iorwerth and Henry III of England.

The only visible remains today, two sides of the rectangular South East corner of the "new castle"'s outer bailey, were built in the late 13th or early 14th century.

[8] Despite the Welsh rebellion led by Owain Glyndŵr, which saw a number of English castles attacked in the early years of the 1400s, it is not known whether Swansea fell to these forces.