Quoted By:
OP here.
The place I slept is pictured. I was at the foot of a mountain, so it was a challenge to find a more or less flat surface.
At noon I napped on a bench for an hour which was very comfortable, so I'm sure that the irregularities of the ground don't mix well with my back. It had felt like the ground with its bumps and stones was deforming my back or somehow deeply pressing to my organs through my skin.
I learned my lesson and will get a mat. If one wants to go all-terrain when sleeping, a mat is a must. Sleeping bag only only works on a mossy underground or when making a bed with fern.
