Through the years, the stands of "Stadion Sparta" were often renovated and extended, but the most radical renovation took place in 1998 and 1999: the stadium was completely rebuilt according to a plan of the architects Zwarts & Jansma. During the renovation, the pitch was turned 90 degrees. At the same time, it was renamed "ENECO-stadion", after its main sponsor. That name was soon replaced by the present "Het Kasteel" ("The Castle"), which had already been the popular nickname for the stadium ever since it was built.