The site of the Battle of Diamond Hill, which took place on the 11th and 12th June 1900, in which 14000 British soldiers and 4000 Boers engaged in battle. Nineteen British soldiers and three Boers lost their lives. During 1961 and 1963, many troops laid to rest in remote cemeteries were reburied at the Diamond Hill Garden of Remembrance.

Lord Roberts, Commander in Chief of the British forces, prepared to occupy Pretoria on 5 June 1900, General Louis Botha left to rally the remnants of the Boer army. Botha had been persuaded to continue the war by the Free State President Martinus Steyn and further encouragement now came with the news that Christiaan de Wet’s, Free State commandos were wreaking havoc with the extended British line of communication between Pretoria and Cape Town. British columns had been defeated at Lindley and Heilbron and rail links were repeatedly being disrupted. The Transvaal commandos were despondent and exhausted after months of defeat and retreat and many had returned to their farms thinking that the war was over. But, encouraged by Botha’s revived determination and the news from the Free State, a core of about 5000  burghers were still willing to fight on. They assembled at Donkerhoek Pass, which today carries the modern N4 highway through the Magaliesberg range about 30km east of Pretoria.
 

Geolocation
-25° 48' 36", 28° 31' 37.2"
Further Reading

 https://www.sahistory.org.za/dated-event/battle-donkerhoek-diamond-hill-marks-continuation-south-african-war

https://magaliesmeander.co.za/news/the-battle-of-diamond-hill-11-12-june-1900/

https://ms-my.facebook.com/sacommuter/posts/our-first-outside-broadcast-event-and-its-of-important-historical-importance-joi/2575219749450099/

https://www.sa-venues.com/attractionsga/donkerhoek.php