Eaton and Waterloo Parks in Norwich were singled out for their quality and because they have remained almost unchanged. Both were designed by Captain Sandys-Winsch, a protege of Edwardian landscape architect Thomas Mawson.
Waterloo Park was restored in 2000 with Heritage Lottery Fund money.
The other registered sites in the Sandys-Winsch series are Wensum Park, Heigham Park and Mile Cross Gardens.
Parks on the register have three grades. Only two, Royal Victoria Park in Bath and Sefton Park in Liverpool, have grade I status.