A burdei is a kind of house that's made in the ground. Imagine digging a deep hole in the earth and then covering it with branches and leaves to make a roof. That's what a burdei looks like! It's a cozy home that keeps people warm and dry, even in the winter. People used to make burdeis a long time ago when they didn't have tons of fancy building materials like bricks or lumber. It's a bit like building a little secret den underground where you can feel safe and snug.