This cache is quite similar to my Mongolian 'Blue Caves' cache (GC9734) featuring some very old rock carvings. These rock art carvings are quite famous in this region in Namibia and date back many thousands of years. This cache might be a bit off the beaten track but the art on the rocks is worth it.
To get to this cache you need to hire a guide at the entrance, either on your own or as part of a group. The guide will give you some basic information about the rock art, but their primary purpose is to protect the art from vandalism. Guides can take you individually through the rocks or you can go as part of a larger group.
You will need about 5 minutes to find the cache and replace it but that shouldn't be a problem since guides typically spend about 10-15 minutes at the rock art for people to explore the area and to take pictures.
Note: Most of the local guides know about this cache, which has turned out to be a good thing. Therefore if you ask your guide about the geocache (or show them your GPS) then they may know what you are talking about and help you in finding it. The downside to this is that the cache may go missing sooner if anything of value is left in the cache. If a guide does help you find the cache then I would recommend a decent tip. If you cannot find the cache then I will also accept a picture of yourself and your GPS infront of the art piece located adjacent to the cache location.
Fall 2008 Update:
The cache has been removed from this site over concerns of damage to the surrounding area. As there is no possibility of a new cache being placed, I will accept logged finds that feature the picture option mentioned in the above paragraph.