I had not spent a lot of time in Waterford, but one thing that struck me forcefully is that the county and provincial borders, following the rivers as they do, really don't make a lot of sense now and would have made even less sense in earlier times. The Barrow, the Nore and the Suir were channels of communication, not barriers; the economic hinterland of Waterford in former centuries must have reached at least as far, if not further, into what we now call Counties Kilkenny and Wexford than it did into County Waterford. So any appreciation of the geography has to start from Waterford as a hub for activities to the north, east and west (and south a little bit).
This is Mocollop Castle, way out west on the border between Counties Waterford and Cork; here Nicholas White distinguished himself as part of the Elizabethan forces besieging the castle in 1571. Not clear how long it has been in ruins.
Going north of Waterford across the county line to Kilkenny, this is Knocktopher Abbey, which may actually be rather more recent than its name suggests; however, not the medieval keep onto which the later building was constructed. The name of the keep? White's Castle - apparently a base for Nicholas White (who is recorded as having established himself at "Whites Hall near Knocktopher").
As he worked his way up the greasy pole of Elizabethan politics, White emulated the famous Jack Horner and pulled out a real plum from the aftermath of the dissolution of the monasteries. Crossing the water again to County Wexford, this is Dunbrody Abbey where he established his residence from 1569 for a few years before politics took him to Dublin. (Unfortunately closed until the summer season starts; I believe it is rather impressive to visit.)
Dunbrody Abbey's estates included the peninsula of Duncannon, which guards the estuary leading to Waterford and parts beyond. The site already included a castle and some fortifications, but in 1587 this was actually taken away from White as the Spanish invasion loomed - because, being Irish-born and a native speaker of the language, he was not considered trustworthy enough to be in control of such an important military asset. The outer walls date from about that time (and featured in the new Count of Monte Cristo film which I might actually now go and see).
My final stop was Wexford town. White's first serious government job, in 1568, was as Seneschal of Wexford and from 1569 Governor of Wexford Castle; I spent some time looking for said castle, but there are no remains of it visible (this is the West Gate of the old town). I guess Cromwell erased it a few decades after White's time.
So, time well spent, from my point of view anyway.