1. Launch a large helium balloon with big words "WE ARE HERE" so the person lost can walk to the balloon.
2. Fly a kite with words on the kite "WE ARE HERE" and let the lost person find it.
3. Play loud alarm sounds for the lost person to walk toward the sound. It can even have words such as "WE ARE HERE" on a mega phone repeat itself.
4. For forest, they should put a large pole with a flag so anyone lost can find their way to the flag.