Joshua set up twelve stones in the midst of the Jordan, in the place where the feet of the priests who bore the ark of the covenant stood: and they are there to this day.
Now it'd be fun-They set up two memorials. They took stones and set them in a pile in the Jordan River, and then they also set a pile up on a bank. It'd be fun to get some scuba gear, since they were there to that day, to see if the stones are still there in the Jordan River that Joshua set up.