<P> After independence the Chief Commissioner's Province of H.P. came into being on 15 April 1948 as a result of integration of 28 petty princely states (including feudatory princes and zaildars) in the promontories of the western Himalaya, known in full as the Shimla Hills States & four Punjab southern hill states by issue of the Himachal Pradesh (Administration) Order, 1948 under Sections 3 & 4 of the Extra-Provincial Jurisdiction Act, 1947 (later renamed as the Foreign Jurisdiction Act, 1947 vide A.O. of 1950). The State of Bilaspur was merged in the Himachal Pradesh on 1 April 1954 by the Himachal Pradesh and Bilaspur (New State) Act, 1954 . Himachal became a part C state on 26 January 1950 with the implementation of the Constitution of India and the Lt. Governor was appointed . Legislative Assembly was elected in 1952 . Himachal Pradesh became a Union Territory on 1 November 1956 . Following area of Punjab State namely Shimla, Kangra, Kulu and Lahul and Spiti Districts, Nalagarh tehsil of Ambala District, Lohara, Amb and Una kanungo circles, some area of Santokhgarh kanungo circle and some other specified area of Una tehsil of Hoshiarpur District besides some parts of Dhar Kalan Tehsil of Pathankot District; were merged with Himachal Pradesh on 1 November 1966 on enactment of Punjab Reorganisation Act, 1966 by the Parliament . On 18 December 1970, the State of Himachal Pradesh Act was passed by Parliament and the new state came into being on 25 January 1971 . Thus Himachal emerged as the eighteenth state of the Indian Union . </P> <P> Pre-independence structures still dot Shimla; buildings such as the former Viceregal Lodge, Auckland House, Christ Church, Gorton Castle, Shimla Town Hall and the Gaiety Theatre are reminders of British rule in India . The original Peterhoff, another Viceregal residence, burned down in 1981 . British Shimla extended about a mile and a half along the ridge between Jakhoo Hill and Prospect Hill . The central spine was the Mall, which ran along the length of the ridge, with a Mall Extension southwards, closed to all carriages except those of the Viceroy and his wife . </P> <P> Shimla is on the south - western ranges of the Himalayas at 31 ° 37 ′ N 77 ° 06 ′ E ﻿ / ﻿ 31.61 ° N 77.10 ° E ﻿ / 31.61; 77.10 . It has an average altitude of 2,206 metres (7,238 ft) above mean sea level and extends along a ridge with seven spurs . The city stretches nearly 9.2 kilometres (5.7 mi) from east to west . Shimla was built on top of seven hills: Inverarm Hill, Observatory Hill, Prospect Hill, Summer Hill, Bantony Hill, Elysium Hill and Jakhoo Hill . The highest point in Shimla is the Jakhoo hill, which is at a height of 2,454 metres (8,051 ft). </P> <P> The city is a Zone IV (High Damage Risk Zone) per the Earthquake hazard zoning of India . Weak construction techniques and an increasing population pose a serious threat to the already earthquake prone region . There are no water bodies near the main city and the closest river, the Sutlej, is about 21 km (13 mi) away . Other rivers that flow through the Shimla district, although further from the city, are the Giri, and Pabbar (both tributaries of Yamuna). </P>

Shimla is built on the top of how many hills