We were reading recently about the Nazca Indians of Central America. They made these huge drawings in the ground that were hundreds of miles wide. When you walk across one you think it's just a pathway, but when you fly over it in a plane you can see that it's a drawing of an animal or insect. The mystery is in trying to figure out how they designed it without being able to see it from above. Did they plot it out mathmatically or use the position of the stars? No one knows.
For art the girls drew pictures with white crayons on white paper. Then they covered the paper with water color paints to see how well they were able to draw without being able to see what they were trying to draw. Here's a picture of Gloria's flower.