Cragside is a country house in the civil parish of Cartington 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 km² forest garden, it was the country home of Lord Armstrong and has been in the care of the National Trust since 1977. 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 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. In 1868, a hydraulic engine was installed, with water being used to power labour-saving machines such as laundry equipment, a rotisserie and a hydraulic lift. In 1870, water from one of the estate's lakes was used to drive a Siemens dynamo in what was the world's first hydroelectric power station. The resultant electricity was used to power an arc lamp installed in the Gallery in 1878. The arc lamp was replaced in 1880 by Joseph Swan's incandescent lamps in what Swan considered 'the first proper installation' of electric lighting. The generators, which also provided power for the farm buildings on the estate, were constantly extended and improved to match the increasing electrical demand in the house. 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. The documentary series Abroad Again in Britain by Jonathan Meades focused on Cragside in episode 2 (2005). In 2007, Cragside reopened after undergoing "total refurbishment."