Street of Facades, Petra, Jordan
Edit: This is the inside look.
Correct. I still suck at this.

I wonder what the purpose of those square holes on the walls is...
I was checking those out while I was there. It doesn't look like the work of the Nabataeans, doesn't
seeseem ornate enough. I suspect they were carved later by
the Romans, Byzantines, or nomads to hang tapestries on the walls to make the khaznaat more livable.

There are still plenty of khaznatts that are being used as homes by the Bedouin tribe of the area. Many are out in the middle of no-where, but set up with tented cafes right outside, selling Turkish coffee, snacks, and cold drinks. They use solar panels and batteries to provide electricity for their refrigerators. The supplies are carried in by donkeys and mules. Prices for these goods are what you would expect for any tourist trap where the tourists are mostly wealthy Westerners and stuck miles from any other amenities.
Two of my children and I walked the whole thing, from the back entrance to the main gate, with plenty of side missions to check out views from the tops of some of the peaks. Almost 10 miles in total.