The creation of the Reserve is considered one of the most ambitious programmes of its kind to be undertaken anywhere in the world. The crater of a long extinct volcano is the setting of Pilanesberg National Park - a fascinating alkaline complex produced by volcanic eruptions some 1300 million years ago. Pilanesberg is one of the largest volcanic complexes of its kind in the world. Its rare rock types and structure make it a unique geological feature. The area is fringed by three concentric ridges or rings of hills - the formation rises from the surrounding plains like a bubble. The structure of the park is termed the "Pilanesberg National Park Alkaline Ring Complex". Ancient, even by geological time scales, this extinct volcano is the most perfect example of an alkaline ring complex. A number of rare (but not necessarily economically important) minerals occur in the park. Pilanesberg National Park rates high amongst the world's outstanding geological phenomena...