A gingerbread house consists of cookie walls that fit together to form a sturdy structure. A thick coating of icing serves as glue between the cookies as well as providing decoration to the outside of the building. Windows of sugar glass give the occupants a view of the outside and let natural light in. A chimney is a common feature at the center of the roof for the escape of smoke from a fireplace or oven inside of the house. Gingerbread houses are often made as centerpieces for the holiday season, and can be decorated in many ways with candies, frosting, and other treats.