Nylstroom, a town of the Transvaal, South Africa, capital of the Waterberg district, and 81 m. N. of Pretoria by rail; altitude 4250 ft. Pop. (1904) 599. It was founded about 1860 and owes its name to the belief of the early Boer trekkers that the river which they had discovered was the head stream of the Nile. The Waterberg gold-fields are 20 m. N.N.E. of the town.