Johannesburg (/dʒoʊˈhænᵻsbɜːrɡ/; Afrikaans:[joˈɦɐnəsbœrχ]; also known as Jozi, Jo'burg, eGoli, and Joeys, and abbreviated as JHB) is the largest city in South Africa. It is the provincial capital of Gauteng, which is the wealthiest province in South Africa. The city is one of the 50 largest urban agglomerations in the world, and is also the world's largest city not situated on a river, lake, or coastline. The city was named and established in 1886 following the discovery of gold on what had been a farm. The city is commonly interpreted as the modern day El Dorado due to the extremely large gold deposit found along the Witwatersrand The name is attributed to one or all of three men involved in the establishment of the city. In ten years, the population was 100,000 inhabitants. While Johannesburg is not one of South Africa's three capital cities, it is the seat of the Constitutional Court, which has the final word on interpretation of South Africa's constitution as well as with issues in connection with constitutional matters. The city is the source of a large-scale gold and diamond trade, due to its location on the mineral-rich Witwatersrand range of hills.
Known as the Transvaal Observatory until 1912, it became the Republic Observatory in 1961. Well remembered for the quality of its Directors, work done on minor planets and the discovery of Proxima Centauri, growing light pollution problems in Johannesburg led to its closure in 1971-1972.