Cathedral Gorge seems like a hidden gem. There aren't many people who visit so if you go, you should have plenty of room to do as you wish. The Gorge was created through volcanic activity millions of years ago which spewed ash into mounds that were filled with water and faulted into the many valleys there are today.
There are some amazing sights to see. Plenty of narrow valleys, and a large valley with a great view that is accessible by a short hike or car. I recommend arriving in the afternoon and photographing the valleys until sunset. The stars are beautiful at night and the formations make for great foregrounds. Want to run a time-lapse all night? No problem, Just let it go and walk to the camp grounds which are just a step away from the Gorge.