The Earth is full of landforms. From waterfalls like the one pictured on the left, to mountains, there are a variety of landforms all over the Earth.

But where do they come from? How are they made?

Landforms are formed through either a constructive or destructive process.

Constructive landforms are formed by the building of earth. These can be formed by the Earth's crust, volcanoes, or sediment.

Destructive landforms are formed by breaking down earth. These are formed from weathering and erosion.

A delta is a landform made by sediment deposits, near the end of a river. It is a constructive landform.

Deltas form when water slows down and sediment piles up at the bottom of a river, forming new land.

Canyons are formed by erosion making them a destructive landform.

Canyons are formed by rivers that erode at the land around it. The erosion by water creates steep canyon walls and a low valley.

Sand dunes are mounds of sand that have piled up from wind erosion. They are constructive landforms.

When wind blows sand in an arid environment the sand is blown in one direction all together. It creates a mound of sand, a sand dune.