In orienteering, "the thinking sport", you use a map and compass to navigate a course through unfamiliar terrain. People of all ages enjoy orienteering as a leisurely walk in the woods or as a competitive cross-country race. The local Bay Area Orienteering Club is a great resource to learn this fun sport. Several "newcomer" events are held each year and children are encouraged to participate. Check out the FAQ page at BAOC.org for a great introduction.
Other sites:
Places to purchase a beginner compass:
1. Local camping or outdoor store