Water Color Sketch
Landscape with Trees and Water
That's mainly because watercolor painting, despite being associated with kindergarten and early grade school classes and the masterpieces you see stuck on refrigerator doors and office cubicle walls, requires considerable skill. That is good watercolor painting requires considerable skill.
Water color is also the basis of fresco painting, for thousands of years the method of choice of painting murals. As to why watercolors - which normally have to be protected from moisture - last for centuries when painted on a wall requires a bit of understanding of the science of the art. There are also some surprises in the history of fresco painting, particularly if you got your knowledge by watching Charlton Heston and Rex Harrison in the Agony and the Ecstasy. But for a bit more about the science and what Michelangelo really did on the ceiling of the Sistine Chapel - no, no, he didn't do that - just click here.
And it is only honest to point out that this sketch was the fruits of what was in effect a short workshop. The teacher - Jean Spicer, a watercolorist of considerable skill and reputation - gave the class this assignment as an exercise. As such it did not end up on a refrigerator door or in an office cubicle, but on a website.