Locate a piece of thick cardboard, sturdy enough to use as a base. Cut small boxes into shapes to form the structure of the castle, taping pieces together to create four-walled towers. Cut flat sheets to make the outer walls and drawbridge, and cut toilet paper and paper towel rolls to the height you desire for corner towers. Add white glue to the bottom of the pieces and place them onto the base. Place a few pieces of tape from the bottom edge of the walls to the base, to hold the walls in place while the glue dries. Once assembled, paint the entire castle with acrylic paints.
Stack one row of craft sticks on top of each other as tall as you want the walls to be and glue together with white glue. To create building tops and other flat surfaces such as the drawbridge, place craft sticks, side by side, and glue them together along the sides. Glue a few sticks underneath the surface, facing in the opposite direction, for support. Cut small pieces of stick to make flag poles to hang medieval banners. Paint the castle, once assembled, using acrylic paints.
Kids of all ages can use flexible foam craft sheets from a craft store to build a castle. Foam sheets provide an ease of use, being effortless to shape, form and cut. Fold the sheets to form towers and walls and glue them together along the edges using white glue. Stack pieces of foam sheets and glue them together to form thicker, stable pieces for building the drawbridge and walls. Attach all of the pieces together, one by one, to create the castle structure. Attach the assembled castle to a heavy cardboard base using glue. For additional details, tie cotton cording from the drawbridge to the castle to look authentic, and cut pieces of blue foam craft sheets to make the water in the mote around the castle.
Recycle plastic butter tubs, boxes, tin cans and tall potato chip cans, and use a paper mache technique to make a castle. Stack the items together on a thick Styrofoam base to create the structure of the castle. Glue the items onto the base using white glue. Make the paste by combining one-part flour with one-part water in a bowl and mix with a spoon. Rip newspaper into sheets, dunk the strips in the paste, and place the papers onto the castle. Make sure to overlap the papers, adding at least four layers of paper to the whole castle. Allow to dry for several hours, and then paint with acrylic craft paints.