If you only have time for a couple of stops in the East MacDonnell Ranges, make Trephina Gorge Nature Park (75km from Alice) one of them. The play between the pale sandy river beds, the red and purple gorge walls, the white tree trunks, the eucalyptus-green foliage and the blue sky is spectacular. Depending on the time of year, you'll also find deep swimming holes and abundant wildlife. There's a rangers station and camping grounds with barbecues, water and toilets.
The Trephina Gorge Walk (45 minutes, 2km) loops around the gorge's rim. The Ridgetop Walk (five hours, 10km one way) traverses the ridges from the gorge to John Hayes Rockhole; the 8km return along the road takes about two hours. Along the way, birders will want to watch for the yellow-throated miner, dusky grasswren and even budgerigars.
The delightful John Hayes Rockhole, 9km from the Trephina Gorge turn-off (the last 4km is high-clearance 4WD only), has three basic camping sites. From here, the gorgeous Chain of Ponds walk (1½ hours, 4km loop) leads past rock pools and up to a lookout above the gorge.
On your way to the gorge, take the turn-off signed 'Ghost Gum'. Just 300m off the main track, you'll find what is believed to be Australia's largest ghost gum, which may be 300 years old and hence predates European establishment in Australia. It's a magnificent specimen.
The road in off the Ross Hwy is sealed for the first 3.5km, then turns to gravel, with some (usually shallow) water crossings to the gorge car park.