Geocaching?

At work the other day we had a team lunch and were talking about the Wolf River in Memphis and different activities around it. A friend at work said that she goes fishing there every once in a while and the last time she was there she found something in the woods. She said it was a metal box and it was chained to a tree. When she was there, the water was up high enough that the box was almost covered. Inside there was a bunch of random stuff she said, but she couldn't remember what it was. Well it sounded like a ridiculous thing to make up, so she convinced me to go after work on Monday to find it again.

We parked by the Chick-fil-a in Germantown and went down to the river (in our work clothes). It wasn't too far, but still strange. The box was still in the same spot!

How strange. We opened up the box and inside were two plastic bags with random stuff in them. In one bag was a pen and a notebook. 

 Somehow my friend from work had stumbled into a Cache. What is a Cache, you ask? I had to look it up on my phone while we were there.
http://www.geocaching.com/
I guess there are over a million Caches (?) all over the world and people go to the website to find the GPS location then go and find it. You are supposed to write in the notebook (or go online) and take something from the box and put something back in it. We didn't have anything to put in the box but we signed our names. The most interesting things were two wooden coins.

Kind of fun, I guess people just go and look for these things wherever they are! Interesting hobby I had never ever heard of. Have you heard of caching?