Hike to the summit of Mica Mountain (8,664 feet), highest point of Saguaro National Park. There are several ways to get to the top of this mountain peak, but all of the hiking routes are long, so set aside a full day to hike this peak.
Since the summit of this peak is in a National Park, this cache is a virtual cache. To record your finding, upload a picture of yourself at the sign at the summit, as in this example. You should also sign the peak register, in a small glass jar under a rock next to one of the concrete footings of the old fire tower. Since this is not a cache container, please don't leave any trade items or travel bugs in this glass jar.
The hiking route that I used was along the Italian Spring Trail, which is described in this article. If you want to get other caches while hiking to this peak, then this is the route that I recommend that you use, because you can also find caches such as Italian Trap Tank near the trailhead and Italian Spring Trail while en route to this cache.