First envisaged as a country lodge and weekend retreat for Sir William Armstrong, this fabulous, eye-catching mansion was developed over 15 years, with the help of Norman Shaw. Much of Shaw's architectural work, described as 'Free Tudor', has remained unchanged since the second half of the 19th century and presents a fascinating mix of mellow, local stone with bold 'Cheshire-style' black & white half-timbering. The elevated position of the house, along the edge of a vast rock face, only serves to emphasise the character and irregular charm that Cragside symbolises. Towards the end of the 19th century, many alterations and additions were made, overseen by both Armstrong and his great-nephew William Watson, who was then living at Cragside and managing the estates. Meanwhile, in 1893, Lord Armstrong purchased Bamburgh Castle.

After his death in 1900, Lord Armstrong's great-nephew inherited both Cragside and Bamburgh Castle, and after this time things took a gradual downhill turn. By 1908 serious debts had been incurred by the new Lord Armstrong, which resulted in the sale of many of his great-uncle's prized possessions, and in 1977 Cragside and a large portion of the estate passed into the Treasury's hands in part settlement of death duties.

Today, managed by the National Trust, Cragside offers the opportunity for visitors to gain some understanding of Lord Armstrong's incredibly inventive and scientific mind, as well as sharing his appreciation of fine art and craftsmanship. Although trained as a lawyer, Armstrong had a naturally inquisitive and innovative nature that led him into engineering. Probably most renowned in the fields of artillery and hydraulic power, Cragside was the first house to be lit by hydroelectricity, with Armstrong building the lakes, the turbines and the power house to provide this source of water power. There was a hydraulic lift installed, and several domestic machines in the laundry and kitchen all powered by water. These inventions may do little to inspire the less technologically-minded, but the beautifully decorated Morris interiors are certainly something to marvel at, and the exotic suite of Turkish Baths situated beneath the Library and the Victorian Billiard Room, are two unexpected and delightful features of Cragside.

Cragside is most memorable for the massive scale of everything: the vast estate covering some 1,700 acres, the substantial lakes, the gigantic rock garden, and the extremely grand house. Armstrong harboured fond memories of Rothbury from childhood holidays and Cragside stands as a memorial to his determination and entrepreneurial spirit.