As part of the Property Development Programme for Kenilworth Castle in Warwickshire, English Heritage created an ambitious reconstruction of the Elizabethan garden which formerly stood on the north side of the castle keep. In order to achieve a reliable representation of the original garden, a programme of archaeological trenching, open area excavation and watching brief was carried out by Northamptonshire Archaeology (now MOLA) from 2004 to 2008. This report discusses the results of the excavations which uncovered for the first time the foundation and culverts of an octagonal fountain basin, described by Robert Langham in a contemporary letter relating to Queen Elizabeth I's visit in 1575. The results of the excavation also clarified to some extent the original dimensions of the garden and the foundation level upon which the fine surfacing detail would have been applied. Contributions to understanding the geometry of the garden's architectural features are made by the identification of a series of rubble-and-mortar-filled pits, which probably formed bases for plinths for structures or other structural elements. The terrace which formed a viewing promenade over the garden was shown to have undergone substantial alteration. The impact of Civil War defences and slighting on the north of the keep and outer bailey wall were investigated. Following this, the area was subsequently cultivated as a kitchen garden and orchard from at least the beginning of the eighteenth century. Twentieth-century activity included consolidation of the castle fabric, the construction of paths and the remodelling of the terrace, and the remains of an ornamental knotwork garden created in 1975. The archaeology of the garden and its surroundings are discussed from the remnants of medieval features through to the present day.