[header] How to find true north without a compass [title] Place a stick upright in the ground so that you can see its shadow. [step] Alternatively, you can use the shadow of a fixed object. Nearly any object will work, but the taller the object is, the easier it will be to see the movement of its shadow, and the narrower the tip of the object is, the more accurate the reading will be. 
Make sure the shadow is cast on a level, brush-free spot. [title] Mark the tip of the shadow with a small object, such as a pebble, or a distinct scratch in the ground.