We had enough snow to make a pretty decent fort. The kids made a snowman to guard the front door. I did most of the digging of the fort. Elizabeth complained that I made the roof pretty thin as she wanted the fort to last a long time but I was worried about a potential collapse so they had to make do.
I drew the line at making more than two bedrooms. There's an emergency slide, steps, a kitchen and play area. But mercifully they agreed that if anyone needed toilet facilities they could go inside.