https://en.wikipedia.org/wiki/Cragside

Cragside is a country house in the civil parish of Cartington, near Rothbury in Northumberland, England. It was the first house in the world to be lit using hydroelectric power. Built into a rocky hillside above a 4 km forest garden, it was the country home of armaments manufacturer, Lord Armstrong, and has been in the care of the National Trust since 1977. The property was eventually opened to the public in 1979.

Cragside, named after Cragend Hill above the house, was built in 1863 as a modest two-storey country lodge, but was subsequently extended to designs by Richard Norman Shaw, transforming it into an elaborate mansion in the Free Tudor style. At one point, the building included an astronomical observatory and a scientific laboratory. The Grade I listed house is surrounded by one of Europe's largest rock gardens, a large number of rhododendrons and a large collection of mostly coniferous trees. One variety of rhododendron is named after Lady Armstrong.

In 2007, Cragside reopened after undergoing "total refurbishment.”