The grass terraces of Duncombe and Rievaulx are unique, and perhaps the most spectacularly beautiful among English landscape conceptions of the 18th century (C. Hussey, English Gardens and Landscapes 1700 - 1750).

It is thought that the 35 acre (14 ha) gardens, which pre-date the era of 'Capability' Brown and Repton by some 60 years and comprise one of the finest Baroque landscapes in England, were completed between 1713 and 1730 to the designs of either Charles Bridgeman or Stephen Switzer, or both. The 'green' gardens were created within an ancient parkland on a virgin plateau 184 ft (56 m) above Helmsley Castle and the Arcadian valley of the River Rye, and were the incentive behind the choice of site for the Duncombes' Great House which was completed by 1718. Vast terraces with classical temples, woodland walks, parterres and a 'secret garden' may be explored in a tranquil setting. There are the occasional breathtaking views and all is within a National Nature Reserve. There may have been plans to link up with the later terrace created by the Duncombes above Rievaulx Abbey.