Unregistered

I once saw this painting in an art history book, so it's probably somewhat famous.

Bottom half of the painting looks like an empty market square, just white stone tiles, no people. There's a low, white brick wall in the middle of the painting going from edge to edge, and one or two small Roman pavilions in front of the wall. Behind the low wall there are some trees or bushes, but mostly clouds and sky. It's like a postcard from ancient Rome, colors are very light.