For much of the late 20th century, Horse Guards Parade was used as a car park for senior civil servants; about 500 were granted the privilege, which was known as the 'Great Perk'. The PIRA's mortar attack on 10 Downing Street on 7 February 1991, which was carried out from a vehicle parked in Horse Guards Avenue near to Horse Guards Parade, although producing no casualties, led to concern about security. In April 1993 the Royal Parks Review Group, headed by Dame Jennifer Jenkins, Baroness Jenkins of Hillhead, recommended that Horse Guards Parade should be restored for public use, and linked to St James's Park by closing Horse Guards Road. The proposal was taken up by the Department of National Heritage but then resisted by senior Cabinet members, apparently under pressure from the civil servants who were to lose their parking places.The parade ground is open on the west side, where it faces Horse Guards Road and St. James's Park. It is flanked on the north by the Old Admiralty and the Admiralty Citadel, on the east by William Kent's Horse Guards – formerly the headquarters of the British Army – and on the south by the Foreign & Commonwealth Office and the rear garden wall of 10 Downing Street, the official residence of the British Prime Minister. Access to this side of Horse Guards Parade is now restricted for security reasons.