This is a sketch that was inspired by me glimpsing a painting at a distance in a house in Udine, not understanding what it was and imagining that it was of a massive rift valley. The concept that I was thinking about was an exoplanet with a rift all the way around, so that there is one population living down in the valley, another population on top, and the only way that they can communicate is by means of hot air balloons (upwards).