named for eminent paediatrician Dr Margaret Harper, whose work on infant diet, care and disease has remained highly influential. Tresillian tailored and altered the house during their 33-year occupancy including subdividing the larger rooms for accommodation, toilets and storage. Measured plans were prepared in the 1950s identifying the rooms and their uses. In particular, a single storey extension, housing a nursery, was added in 1939 between Margaret Harper House and Greycliffe, which involved demolition and alteration to previous work. The architect added a rotunda to this suite of rooms. A toddlers' room was constructed in 1953 on the north east corner of the enclosed verandah and Margaret Harper House was constructed to the east in 1939. The garden to the north of Greycliffe was well used by the Tresillian patients and staff. During the 1930s, Matron Kaibel, who resided at the site for 23 years, established a sunken garden to the northeast of Greycliffe with associated paths and plantings. The facility closed its doors on 10 October 1968. The property was added to the lands to be administered by NPWS on 4 May 1970. Under National Parks stewardship, Greycliffe was repaired and restored to its nineteenth-century layout. The Lady Edeline and Tresillian external additions were removed, in particular, the additions attached to the north and east of the former stables. Some of the internal features relating to the Lady Edeline and Tresillian phases were retained. The upper floor of the stables had not been not altered and still retains its mid-nineteenth-century plan. In 2002 the gardens around Greycliffe were reconstructed. Management by NSW National Parks and Wildlife Service (1967-present) When the NPWS assumed management of Nielsen Park in 1968 they set about making the Park more open and focused on both public recreation and protection of the natural environment. Fencing on the beach was removed, free access was given to the swimming enclosure and the Dressing Pavilion, car parking was banned and two picnic shelters were removed. The wharf was demolished in 1979 along with swimming platforms, pontoons and a diving tower. Women's change sheds near the wharf were removed as were fireplaces at Vaucluse Point. At this point, Greycliffe House became the new administration centre for the Sydney District of NPWS. In 1989 a new steel framed workshop and compound was built in the old quarry site behind Mount Trefle. Throughout the 1970s various restoration works were undertaken to