Any picture of the bottom of the stream or lake is changeable due to its stony, rocky or plant mosaic structure. The bottom appears variable in shape and colour. Over it water is rippling and we see it as the trembling surface. Some plants like algae, cyanobacteria and liverworts can grow there. Sun adds reflections and shadows to this phenomenon. It is a great pleasure to look at the bottom of the stream or lake through such a moving water. There are then created very attractive moments of our being in mountains.