tin foil
water (from hose, bucket or watering can)
A slope to build your river on or something to prop up your river to make a small slope.
Small bottle cap to be your boat.
With your tinfoil build a long river.
Set your river up on a small incline/slope or create one
Make sure to create some sides to keep the water in.
Once your river is on a small incline or slope set up your water source.
You can use a hose on low and let the water trickle down. You can use a watering can or a bucket.
Using a bottle cap you can make a sailboat with a toothpick (glue) and paper for a sail or you can just have fun with the bottle cap traveling down your river!
Idea taken from: The Joys of Boys