Gua Damai means Peace cave (gua=cave damai=peace) ...
Damai wall is a 300+ foot crag with mostly shorter routes on it, though a few do venture to near the jungle-choked top. The area at the base is open and clear, sporting a bathroom house for the local soccer fields and a tree for shade. The stripped an defunct remains of an outdoor artificial climbing wall lie 50 meters from the wall, a remnant of when the government was actively promoting climbing there. The sport took witha few locals, but not with the great masses. Perhaps the heat of day puts them off.
From the main caves area, and the famous staris that your cabbie has no doubt tried to drop you at, continue to where Jin Batu Caves road passes a few service stationand reaches Jin Taman Industi Bolton 1. Take this left, keeping the "green area" on your left, to JTIB 3, and go left again. Take this down to a small residential area, again staying on the roads such that the green hillside is on your left. After you pass through a few last houses, you will see a mosque, whereabouts you will look left. Down a slight hill there should be some soccer fields and a defunct 10 meter climbing wall near an open area with a large cliff behind it. This is Damai wall.
You can use the GPS coordinates I have linked on the googlemap function on the site to get precise images and the available out-of date map. The shantytown is gone (they were squatters) and the local pond has been drained for industrial space. All environmental qualms aside, that might be a good thing for climbers, unless you like dengue fever...
We had the best luck telling the cabi Pingiran Batu Caves Bus Station once there you should be able to see the crags (Red Rocks [high right], Damia Wall [big center], and White Wall). Try to get the cabi to take you closer or get out and walk. Bathrooms were locked when we were there and wild dogs were around and lots of kids coming by so I wouldn't leave your gear too far away. Location did not feel super secure, if you can I would walk through the neighborhood to the west verses the high density neighborhood to the east. After climbing we were able to walk back out to the main road and catch a cab in about 15 minutes.
Climbs were good in general and hardware appeared secure and well placed. The upper cave space has some climbs not in the guide. Unsure of legality but if it was raining I would head there to stay dry and climb.