Detail of wood panelling in St. Florian Abbey, Upper Austria +

frosted dunes on Mars.

Sand dunes cover much of this terrain, which has large boulders lying on flat areas between the dunes. It is now late winter here in the Southern hemisphere, and these dunes are just getting enough sunlight to start defrosting their seasonal cover of carbon dioxide.

https://photojournal.jpl.nasa.gov/catalog/PIA15881