waterfall

When water flows over hard rock and soft rock, the soft rocks erode creating waterfalls. As the erosion processes continue, the falls move backwards, in the opposite direction of the water

A waterfall on the Tabacon river in Costa Rica. This is a volcanic area, and hot springs abound, feeding into the river network. One third of Costa Rica is given over to national parkland and nature reserves.

Cumberland Falls, Kentucky. The Cumberland, a branch of the Ohio River, rises in Kentucky, winds southwest into Tennessee, and then turns north and back into Kentucky. The horseshoe shape of the falls gives it the nickname ‘the Niagara of the South.’

The Iguaçu falls are situated on the Iguaçu river, on the border between Brazil and Argentina. Set in the rainforest, these falls – 275 separate cataracts – are nearly three times wider than the Niagara Falls.

Virginia Falls on the Nahanni River in northern Canada. In 1978 the Nahanni National Park was the first ever to be granted World Heritage status by UNESCO, the United Nations Educational, Scientific, and Cultural Organization.

Cascade of water in a river or stream. It occurs when a river flows over a bed of rock that resists erosion; weaker rocks downstream are worn away, creating a steep, vertical drop and a plunge pool into which the water falls. Over time, continuing erosion causes the waterfall to retreat upstream forming a deep valley, or gorge. Good examples of waterfalls include Victoria Falls (Zimbabwe/Zambia), Niagara Falls (USA/Canada), and Angel Falls (Venezuela).