We have done a couple of trips to this fantastic slot canyon full of petroglyphs out in Death Valley. It is a challenge to get in to see them. You will need someone with climbing ability and rope to get up to the main grotto with many of the petroglyphs. The canyon is full of dry falls and slick rock, but the site is certainly worth it!
This is a great and unique place. If you go out and visit it, please do not disturb it.
Also, check out the Dzrtgrls trip report on this trip.