Can anyone help?

Thanks Craig - it was my question.

Lots of interesting history including a Google street view first ... http://en.wikipedia.org/wiki/Plas_Newydd
The heir apparent is the present holder's son Charles Alexander Vaughan Paget, Earl of Uxbridge (b. 1950).
The heir apparent's heir apparent is his son Benedict Dashiel Thomas Paget, Lord Paget (b. 1986)
Given that the 5th Marquess bankrupted the estate, there's apparently not much to be heir to.
Beautiful Wales!