The archipelago of Indonesia was under colonial occupation for more than 350 years until its independence in 1945. The built environment of towns and cities at that time was similar to that of today with fewer environmental problems and without multi-storey buildings. Even in those days however, in several big cities such as Jakarta and Semarang, severe environmental problems had already occurred in the form of shantytowns. Basically, as in many developing countries, the structure of Indonesian towns and cities consists of planned and un-planned areas. In the case of Indonesia, the un-planned areas are known as kampung or traditional villages. They are frequently overcrowded; lack urban infrastructure and lack (public owned) open space.