Happy you found something worthwhile and it wasn't all crap. Scary to think you can visit a place and be all done within 3 days and there is nothing else to entertain you. I am not one who falls for tourist traps and tend to avoid them at all costs.
there was plenty more to do but the elevation affecting my ability to breathe was keeping us from being able to do most of them. For someone who isn't affected by this they could stay in this place for weeks and still have lots left to do.
Yes altitude is draining and takes time to become acclimatized. I suffer from sinus issues living in Johannesburg and it is all down to the high altitude and mine dust floating in the air. I have never had sinus issues in my life and a good reason to move away at some point.