Foundry Canyon is a nice route in the Black Mountains of Death Valley. There are some huge rappels that offer fantastic views and require a 300 ft. rope. The canyon can be done with 200 ft. ropes if you bypass these two rappels, but you will be missing out. The shuttle back to the trailhead is long so plan on driving in the dark. Bring rappelling and anchor gear for rappels up to 280 ft. and 70 ft. of webbing for sling placement.