Sol LeWitt had a new and controversial idea about art: That the most important aspect of it is the idea behind it. That's why he's called a "conceptual artist." He calls this pyramid a "structure" instead of a sculpture because it's more like architecture. He made the plans and a set of instructions, then a team of engineers and stone masons built the pyramid right here on this site in the Sculpture Garden. Then, he gave it his final approval. Can you spot the basic shape here?