Geocaching can be a dangerous game...
A big risk of geocaching is taking a tumble, uneven ground and distraction is a recipe for a fall. One way to avoid this is not looking at your GPS device while walking, my mate Rick rolled his ankle doing exactly that last year. Stay safe out there. LAstley remeber to take plenty of water and a first aid kit while caching.
You are looking for and ammo tin, be gentle with it.