I went with my parents to southern Utah and to Disneyworld in Florida. The 'attractions' in Utah were the National Parks there. Not very man-made true. But at times you could believe you were seeing the ruins of ancient temples, or Ozymandius's summer palace.
Bryce Canyon is an incredible place - the scale is truly big like BIG, the place stretches out of sight. The rock (and there is plenty of it) is multi-coloured thanks to different geological ages. In many places pillars of stone rise skyward. These 'hoodoos' have been sculpted by nature into fantastical shapes.
Also incredible there is the heat (up in the 100 degrees Fahrenheit and beyond.) At least it is dry unlike Florida which was humid. Florida felt as uncomfortable despite being 20 degrees cooler. Life adapts. With the aid of air-conditioning. Chipmunks and birds have learnt to hide out inside vehicle grilles.
Cedar Breaks was awesome like Bryce but quite different. It is a vast cleft in the Earth. You're a long way up in the world and it was quite cool even in June (in winter it's snowbound.) Cedar Breaks suffers from constant erosion being on a different side to Bryce. You don't get the rock sculptures but it is a great place if you want to see geology in action.
Zion Canyon you have to use the bus to get around as you're not supposed to drive in unlike Bryce. There is a trade-off between enabling people to see nature and preserving nature. We weren't able to do the trails in Zion (the heat was oppressive for one thing.) I did walk to see Weeping Rock where in the midst of barren dryness water falls down like rain. Courtesy of the rock here being porous and holding masses of water.