The last few days we've been stuck inside due to late April snow advisories and frigid temps, so we decided to get creative - blue sand, shovels, dump trucks, and excavators. We laid out a giant tablecloth, filled a plastic bin with Crayola's blue sand, and threw in some of their digging toys.
They were very serious about their castle building. I kept saying, "boys look up here and smile." Sawyer would say, "not yet mom, I'm still working." Now that it has warmed up again, the "sand box" is outside :)