on the wall

What is the correct term to refer to the outdoor toilets that are found at trail heads and roadside overlooks these days? Outhouses? Latrines? Pit toilets? Ah no matter - you know what I mean, don't you?

After finishing my hike along Bow Lake this afternoon I locked my gear in the car and walked over to make use of the "facilities". I had to run back to the car and grab my phone; I needed to share the artwork from the wall of the oh so convenient outhouse.