Sirimathipaya Mansion houses the Prime Minister's Office.
It is located on Sir Ernest de Silva Mawatha (formerly Flower Road), Cinnamon Gardens, Colombo, Sri Lanka.
The mansion was built in 1916 by Albert Emmanuel de Silva, a wealthy businessmen for his son Sir Ernest de Silva who was one of the richest people in the country, during which the house was equipped then with horse stables and tennis courts.
In 1978 Prime Minister Ranasinghe Premadasa had the building renovated and moved the Prime Minister office into the mansion.
[3] The LTTE carried out a suicide bombing at the Prime Minister's Office, on 5 January 2000, in an attempted assassination, in which a female suicide bomber detonated a bomb outside the building, killing thirteen civilians and three police officers attached to the PMSD.