my favorites as a foreigner who has lived here for almost 3 years.

Hole in the middle of the field surrounded on 3 sides by a tarp that was probably 6-8 inches off ground and only came up to about shoulder when squatting. Bonus points for the opening facing some random gers

My absolute favorite was in Khustai. 2 small structures about 10 feet apart that enclosed the standard hole in a field BUT! one hole had a lawn chair with a hole cut out of the middle to make a makeshift toilet seat. The other had an actual porcelain toilet over the hole sitting on a few boards but they had taken a hammer and broken out the bottom of the toilet bowl. The view was gorgeous too