Landscape

A valley is the space between two hills or mountains. Valleys often have a river flowing through them, and are full of fertile soil that has been washed down from the surrounding hills. Many towns and villages are built in valleys.

A volcano develops where parts of the Earth's outer crust are either coming together or pulling apart. Many of these places are deep under the sea, but some are on land. The most distinctive volcanoes are cone-shaped mountains made of ash and lava, like the volcano in the picture.
Volcanos can be very dangerous and erupt without much warning. The area around them can be prone to earthquakes, and water that flows from the ground near them can be very hot - called hot springs. When a volcano erupts, molten rock and ash can be thrown huge distances, and can even bury an entire town.

Waves on the surface of the sea or a lake are caused by wind blowing over the surface. The longer the wind has been blowing in the same direction and the deeper the water is, the larger the waves can get.
Waves usually only break and make the familiar frothy edge on the wave when they reach the shore. They sometimes break out at sea when they get too steep. Surfers like to surf on breaking waves. The wave in the picture is breaking onto a beach.

Wilderness is a name given to any area that is still in its natural state, where there are no farms, mines or people. Only wild animals live in the wilderness.