Camping

Camping is a great activity that I'd highly recommend. One thing that is a must when going camping is a campfire. There are however a few steps one must take before creating a campfire. One of these steps usually includes finding rocks to surround the campfire in order to ensure that the fire doesn't spread wildly.

Here's where the fun begins. If you're going with friends and want to give them a huge shock, use river rocks. Not only do they look nice and smooth, they certainly carry a nice surprise. Quite a few of them will have tiny bits of water trapped inside which will turn into steam when heated. This will cause a rapid internal expansion leading to a nice boom.

And that's the cheap way to get your hands on what can be considered as "less" dangerous grenades.