Portsdown Hill is a ridge of chalk that lies to the north of Portsmouth Harbour on the South Coast of England. The north side of the hill is farmland, horse paddocks and public open space, while the south side is a mix of chalk grassland and scrub, much of it designated as a SSSI (Site of Special Scientific Interest).
This website describes the open spaces managed by the staff and volunteers of the Portsdown Hill Countryside Service. The impressive array of wildlife and the efforts to bring Portsdown back into a favourable condition are described with the hope that it encourages everyone to appreciate the Hill for the valuable resource it is.

Horses below Fort Widley

There are other areas on nature conservation interest on the Hill, including SINCs (Sites of Interest for Nature Conservation). A variety of landowners and agencies own and manage the rest of the hill including the MoD, local authorities and utility companies. Within these ownerships, fragments of the once widespread chalk downland habitat remain.

Until the 1950's, the south face of hill was regularly grazed, producing a landscape dominated by grassland in which patches of scrub would have expanded and contracted as grazing pressure increased and decreased over the decades. With the decline of grazing, coarse grasses and scrub rapidly took over. The south face of the hill is now a patchwork of chalk-quarries, woodland, scrub, and grassland.

Since 1994, a concerted effort has been made to expand the grassland to its earlier dominance. A grazing programme was initiated which has required much fence-building, as well as scrub clearance, by both hand and machinery.