Hardwell Castle or Hardwell Camp is classed as an Iron Age valley fort, although, like nearby Cherbury Camp, it is not clearly in a strategic or easily defended position. It lies halfway down the scarp slope of the White Horse Hills and is tucked away in a curve, invisible from most angles. This particular positioning suggests its builders had a specialist purpose in mind, although exactly what that may have been remains a mystery. It is 'multi-vallate', like Cherbury Camp.