'[It] was built in 1628, as appears from a date on a chimney-piece, with the words Philipus Mac-grath.  It is said the occasion of building the castle was a dispute between McGrath and his wife, who would not be reconciled until he had built her a castle on her own jointure, to do which he had such contributions from his vassals, that when it was finished, he was much richer than when the work began.  A great quantity of oak was employed in this building, which is not more than a century erected.' (3)

Indeed the new castle was hardly a castle at all but rather a fortified mansion-house erected in the shape of a cross with many battlements, gables and chimneys.

Although Phillip McGrath departed from Mountain Castle in 1628, it is highly probable that he continued to lease the surrounding lands from Gearld FitzGearld of Dromana, (4) although who, if anyone, resided in Mountain Castle following Phillip's departure we cannot say.

Although the McGraths didn't own the lands at Mountain Castle they did possess quite a considerable portion of lands nearby at Sleady Castle.  The Civil Survey of 1654 shows that 800 acres of Curraghnasleady and Ballykereene was owned by Phillip McGrath of Curragh na Sleady, 'Irish papist deceased'.  Whether Phillip inherited these lands as part of the McGrath inheritance or whether they were acquired through the marriage of Phillip to the daughter of Lord Waterford, it is impossible to say.  Certainly that Smith reports that Sleady Castle was built on her own jointure would suggest the latter.

(3) Charles Smith, History of Waterford, 1746.
(4) Rev. Richard Hopkins Ryland in his History Of Waterford City & County 1824 has this to say of the FitzGearlds:
'Dromana, in the parish of Affane is one of the most magnificent demenses in Ireland ..........The Lords of the Decies, the ancient proprietors of Dromana, derived their descent from James, the seventh Earl of Desmond.  In 1561, a descendant of this nobleman was created Baron of Dromany and Viscount Desses, and dying without issue, his possessions but not his titles, descended to his brother Sir James Fitz Gearld who removed from Cappagh to Dromana, where he died in December, 1581.'( lch. 315/316)