Joshua 4:8-9

And the children of Israel did so as Joshua commanded, and took up twelve stones out of the midst of Jordan, as the LORD spake unto Joshua, according to the number of the tribes of the children of Israel, and carried them over with them unto the place where they lodged, and laid them down there. And Joshua set up twelve stones in the midst of Jordan, in the place where the feet of the priests which bare the ark of the covenant stood: and they are there unto this day.