Each of the national heritage agencies for England, Scotland, Wales and Northern Ireland offers protection to historic designed landscapes. The level of protection, and the mechanisms for this are different in each case.
The different regimes are summarised below, based on information from each agency's web site.
England
Historic England compiles the Register of Parks and Gardens of special historic interest in England. It currently includes some 1,600 designed landscapes of many different types.
Scotland
The Inventory of Gardens and Designed Landscapes is compiled and maintained by Historic Scotland and can be consulted on-line.
Wales
Parks and gardens thought to be of national importance are included on the Cadw/ICOMOS Register of Parks and Gardens of Special Historic Interest in Wales.
Northern Ireland
The Northern Ireland Environment Agency(NIEA) maintains the Register of Parks, Gardens and Demesnes of Special Historic Interest, which is available online.