The construction of the superstructure commenced on 1 April 1994. Interiors with furniture were completed on 1 January 1996, the spires of Tower 1 and Tower 2 were completed on 1 March 1996, and the first batch of 'PETRONAS’ personnel moved into the building on 1 January 1997. The building was officially opened by the Prime Minister of Malaysia's Tun Dr. Mahathir bin Mohamad on 1 August 1999.[6] The twin towers were built on the site of Kuala Lumpur's race track.