These vast expanses of reclaimed land, which until the 1970s were industrial dockyards, were in the early 1990s converted into residential areas. Contemporary interpretations of traditional local housing (Java-eiland) border its three vast residential complexes (KNSM-eiland). The two peninsulas of Sporenburg and Borneo-eiland have extensive low-rise family housing with roof terraces or patios. A successful exercise in mixed social housing, a concept which is very important to Amsterdam.