Walls are in very much different sises and types, this cache is located in a nice wall created by artistst who have stayed here for a week. They created 3 years ago some nice walls without any cement just by stapling the stones. Please remember that while looking for the cache.
The cache is located at a side branch of the Hoarusib river bed, when it is raining the rain will make the terrain even more challenging.
If the canyon is inaccesible due to water then you can reach the cache by taking the main road to Orupembe and after a few km's past the lodge there is a left turn to the riverbed.
However you definitily need a 4 x 4 car and the skills to drive 4 x 4. And it is preferred to not go by you own but in this remote area it is wisely to travel by at least two. No cell phone coverage in the wide area.
The best way to reach the cache is enter from Puros then follow the Hoarusib river bed and then turn into the side branch to the cache.