Tiong Bahru is a housing estate located within Bukit Merah Planning Area, in the Central Region of Singapore. Built in the 1920s, Tiong Bahru is the oldest housing estate of the city-state. It was the first project undertaken by the Singapore Improvement Trust (SIT), a government body administered by the British colonial authority, to provide for mass public housing in Singapore. The main estate consists of about 30 apartment blocks with a total of over 900 units and also high-rise HDB flats and condominiums along Boon Tiong Road, Jalan Membina and Kim Tian Road surrounding the main estate. The apartment blocks in the main estate are made up of two to five-storey flats and the units are assorted three to five-room apartments.