shape, with twenty corners. It was built on the site of the previous large ring work fortification in at least three stages, initially by Hugh de Lacy (c. 1174) and then in 1196 and 1201-5 by Walter de Lacy.The castle interior was partially the subject of archaeological digs, by David Sweetman of the OPW in the 1970s, and more extensively by Alan Hayden in the 1990s.

The surviving curtain walls