Article about making an area suitable for reptiles: needs sunshine, so put it on the S side of the valley.
Many years ago my then gf gave me directions to her friends' house. Roughly: along A-road to village, 2nd. R, house some way down on R, sundial on front of house. I said that it would be on the L. She thought for a moment then asked how I knew that. Well, N along A-road, R, so heading E, house on R would face N.
A sundial is a solar device - it stops when in shade. Needs a back-up battery.