Organ Pipe Cactus National Monument Organ Pipe Cactus National Monument is a little less traveled then the Saguaro National Park. All the roads are unpaved and pretty rough in some areas. You can travel them in a 2 wheel car though. As you can see in this picture the cactus has a number next to it. This refers to an informational pamphlet you get as you drive around. There is also some nice hiking in the monument. Choose another thumbnail from the list on the left, or return to the front page.