Running water has a massive influence on the shape of the countryside, creating valleys as it erodes the soil and rocks on its journey to the sea. As a river valley flattens out, the water can slow almost to a standstill, forming lakes and depositing the material it eroded during its fast-flowing stages. Where it comes up against harder rocks, or where tributaries meet the steep sides of a valley, waterfalls are formed. These can be truly spectactular and their statistics astonishing.
Take for example the Angel falls, the water drops vertically without touching the cliff face, for eight hundred and seven metres, a height that is more than most of the hills and mountains in the UK! When you take into account the three waterfalls that make up the Niagra falls in North America, you have the falls with the highest flow rate.
But small can be beautiful too, the Bigar waterfall (pictured above) is considered by many to be the most unusual and beautiful in the world. Located exactly half way between the north pole and the equator, water from a nearby spring situated in a cave joins the upper Anina River via these 8m high falls. The most interesting thing about this waterfall is that it is always coated in a curtain of moss, shaped like a large green bell. The water spreads across the moss and trickles off the bottom like a thin curtain, which in certain lighting conditions can look almost luminous.