Brimham Rocks, once known as Brimham Crags, is a 183.9-hectare (454-acre) biological Site of Special Scientific Interest (SSSI) and Geological Conservation Review (GCR) site, 8 miles (13 km) north west of Harrogate, North Yorkshire, England, on Brimham Moor in the Nidderdale Area of Outstanding Natural Beauty. The site, notified as SSSI in 1958, is an outcrop of Millstone Grit, with small areas of birch woodland and a large area of wet and dry heath.
The site is known for its water- and weather-eroded rocks, which were formed over 325 million years ago and have assumed fantastic shapes. In the 18th and 19th centuries, antiquarians such as Hayman Rooke wondered whether they could have been at least partly carved by druids, an idea that ran concurrently with the popularity of James Macpherson's Fragments of Ancient Poetry of 1760, and a developing interest in New-Druidism. For up to two hundred years, some stones have carried fanciful names, such as Druid's Idol, Druid's Altar and Druid's Writing Desk.
Brimham Rocks has SSSI status because of the value of its geology and the upland woodland and the acidic wet and dry heath habitats that support localised and specialised plant forms, such as chickweed wintergreen, cowberry, bog asphodel and three species of heather.