Ellerslie is a beautiful colonial building, which is also known as Raj Bhawan. It is currently serving as the Secretariat of Himachal Pradesh. The structure was designed by Lt. Col. H.E.S. Abbott during the British reign and was under the control of the military department of Punjab till 1886. The Summit Hall is named after the historic Shimla Agreement signed between India and Pakistan in the year 1972. The building, featuring three floors and 143 rooms exhibits captivating architectural style.