Founded by St Marcellin Champagnat from France in France, the Marist Brothers expanded their Koch Street monastic school to Observatory in 1924. In the 1970s, in defiance of the apartheid government, it became one of the first non-racial independent schools in South Africa. Girls joined the school in 1980 with the incorporation of the Ursuline and Holy Family convents. In the 1990s, it educated the children of returning exiles. Later in 2008, in the context of xenophobic violence that swept South Africa it welcomed refugee children.
15 Eckstein Street, Observatory