I doubt the age is 300 yrs. It could be 300000. Mpumalanga is reported to 1150 to 250000 but I say about 210000. Regardless the megalithic calendar recorded the retrograde cycle which equals 2190 a cycle by 12, a complete cycle = 26, 280. So it is at least: 26, 280 yrs. It is figured that the Africans had to watch the skies for at least 26, 280 to know it was cyclic. Nabta Playa was calculated to be 10, 500 by Buval. I calculated the Sphinx: the Age of Leo 2190 x 7= 15330 yrs, the Age of Aquarius back to Leo. The megaliths are found all over Africa and were made by the Twa people, the first people. The San of the Twa people in South Africa, are about at least 210000 years old.