When Johannesburg was proclaimed in 1886 on the triangular site Randjeslaagte, the area of the town was two and half square km. Randjeslaagte was a piece of ‘uitvalgrond’ – land left over from the farms surveyed around it. This beacon marks the apex of the triangle with its base running along Commissioner Street, from End Street in the East to Diagonal Street in the West. These two and half square km remained the municipal area of Johannesburg until 1901. The original surveyor’s beacon was a white pole fixed in a cairn of rock. It was declared a National Monument in 1965 and the cairn smoothed with cement.