The easiest way to get to the Cockcrow Hill area of Wisley Common, where the barrow and mound are, is to start at the car park / visitors centre for Wisley and Oakham Commons (840 acres in all!) at TQ079587. The visitor’s centre consists of toilets, a small shop and a little local info (nothing about the ancient sites though). You can’t turn in towards the car park if you are coming from the south-west (i.e. if driving towards London) – you have to go up the M25 junction and return.
Just to the right of the visitors centre, take a path (marked ‘Horse Riders’) up and over Curries Clump, which is strewn with condom wrappers and tissues. I guess this area is a perfect woodland cruising spot or something, being so close to the junction of the A3/M25? As you come down the clump the footbridge over the huge A3 is on your left. As you get to the other side you are now in Wisley Common, where some maps and info are pined up on a board and say that both the mound and barrow are Scheduled Ancient Monuments.
The easiest way to get to the barrow is to follow the woodland road around to its end, close to the A3. The huge barrow is then on your left, about 40 metres in diameter and 5 - 6m high I’d guess. There are lots of smaller mounds around the area, but I presume it’s this big beastie that is the barrow.
I found a this on the web....."This was excavated in the early part of the 20th century and signs found of a cremation that had taken place thousands of years before, There were signs also of an excavation that is believed to have been made during the 18th century, during a search for iron ore; and certainly the parallel trenches which cut across the common were also made in the search for iron."