VisitBritain - Welcome
A National Trust (www.nationaltrust.org.uk) site, Cragside House and Gardens (www.nationaltrust.org.uk/main/w-vh/w-visits/w-findaplace/w-cragsidehousegardenandestate/) is just near Morpeth in Northumberland.
I think it was the first house in the world to be lit by electricity - and it has loads of really interesting gadgets and gizmos, which were very much ahead of their time.
I went there all the time as a child - it was a real treat. Has gorgeous gardens - you can just wander around them for ever - particularly famous for its rampant Rhododendrons!