The Northumberland estate of Cragside was made famous when it became the first house in the world to be lit by hydro-electricity.
Now it is going back to being powered by water again.
And the equally famous Northumberland actor, Robson Green, was the man to switch the power back on.
The modern hydro system is a 17-metre Archimedes screw, an old system used to generate power.
It can generate around ten percent of the electricity the property needs.
The former home of Lord Armstrong has been given a modern upgrade.
in 1878, his house at Cragside Hall in Northumberland became the first in the world to use hydro-electricity.
A new hydro system has been installed to power the house and is being switched on this evening (July 29).
A 140 year old Scots pine growing at the National Trust's Cragside in Northumberland has been officially declared the tallest in the UK.
At forty metres tall it's the same height as 10 double-decker buses stacked one on top of the other - It was one of seven million trees and shrubs planted in the second half of the 19th century at the estate
The life of the Victorian stately home Cragside is being brought to life this month.
Actors will play the roles of its owner, Lord Armstrong, and other key characters at the house in Rothbury.
The National Trust says it wants to highlight life for those working below stairs.