Sri Temasek is a two-storey detached house built in 1869 which is sited within the grounds of the Istana in Singapore. During the island's colonial era, it served as the residence of the Chief Secretary. Since gaining self-governance from the United Kingdom in 1959, it has been the official residence of the Prime Minister of Singapore, though none of the prime ministers have ever lived there. Together with the Istana, it was gazetted a national monument on 14 February 1992.