Newport Castle was established in 1191, but there is no surviving fabric thought to pre-date the late thirteenth century. The surviving remains include a curtain wall and of four towers at the angles of the work, one of which, the gatehouse, now forms a private residence built in 1859 in a nineteenth century romantic style. The residence has an L-shaped plan with basement, a three window front and slate eaves roof. The porch has a pointed arch and crested roof tiles. The medieval remains also include a roughly quadrilateral ringwork, c.50m across, circled by a wide moat, part of which appears to have been utlised as a fishpond.
(source Os495card; SN03NE25)

(Source CADW listed buildings database)
J Hill, RCAHMW, 24 September 2003