What to do there
6 steps. Tap one when it's done.
People have hidden small waterproof boxes in parks, on trails and behind signs all across Lambton County, and posted their GPS coordinates online. Your job is to find one. There's a logbook inside to sign.
Tell us about the activity. Please leave out names and contact details.
Setting up the app, and coming along. Caches can be near roads.
6 steps. Tap one when it's done.
Your phone listens to satellites orbiting about 20,000 km up. Each one is broadcasting the exact time; the phone compares how long the signals took to arrive from several of them and works out where it must be to hear them all with exactly that delay.