Rashtrapati Nivas on Observatory Hill, Shimla: the Viceregal Lodge that now houses the Indian Institute of Advanced Study
Background
From 1823 onwards the Governors-General and later Viceroys of India moved between unsuitable summer residences at Shimla, until Lord Lytton chose Observatory Hill for what was to be the final Viceregal address in the town. The hill takes its name from Observatory House which was built in 1840 by Captain J. T. Boileau. The institute that occupies the building records that Observatory Hill is a watershed standing figuratively astride India: the waters from one side of the hill flow down to the Bay of Bengal, and the wash from the other heads towards the Arabian Sea. Lord Dufferin persuaded the Secretary of State for India, Lord Randolph Churchill, to sanction a project that was finally to cost thirty-eight lakh rupees, with the annual upkeep of the estate estimated at one and a half lakh rupees. Henry Irwin was appointed architect and chief superintendent of works, work on the site began in 1886, and Lord and Lady Dufferin moved into the building on 23 July 1888. The huge estate of 331 acres is somewhat smaller today, but the estate is still a princely 110 acres. The Simla Conference, called by the Viceroy Lord Wavell to propose the reconstitution of the Viceroy's Executive Council, was held at the Lodge from 25 June to 14 July 1945; after a Cabinet Mission was sent, a tripartite conference between the Congress, the Muslim League and the British took place at Viceregal Lodge from 5-12 May 1946. The estate passed to the President of India after Independence in 1947, the building was renamed Rashtrapati Nivas, and the Indian Institute of Advanced Study now works there.
In plain words
Viceregal Lodge — The Viceroy of India's summer residence at Shimla, renamed Rashtrapati Nivas after Independence.
Watershed — A ridge that separates two drainage basins and sends rainfall to different rivers or seas.
Cabinet Mission — A British mission sent to work out the modalities by which power could be transferred to Indians.