Organize several items to create an obstacle course. Ideas might include large boxes, jump ropes for setting up borders, balance beam, chairs, tables, etc. If equipment isn't available, you can create a course using tape on the floor. Use a large space to construct the obstacle course. Provide paper and crayons for the children to create their blueprints.
Explain to the children that they are going to construct an obstacle course that will be fun to move through when it is complete. Display the materials to be used for the course and the space. If appropriate, the children could suggest what materials to use for the course.
Have the children make a blueprint by listing the materials and drawing a picture of how they want the obstacle course to be put together. This can be done with a partner or in small groups.
Establish the space in which the children have to build. With supervision, have the children construct their obstacle course and maneuver through it. Possibly incorporate races and games.
After construction and use, have the children think about ways it could be improved for efficiency or for more fun. Have them draw alternative sketches of their blueprints.