Water reaches the rocks through outcrops of rock on the rim of the basin.

Artesian basins are important sources of water throughout the world.

The London and Paris Basins are artesian basins. London gets much of its drinking water from the rocks below the city. The fountains in Trafalgar Square used to rise up without any pumping - it was simply artesian water pressure.

The world's largest artesian basin is the Great Artesian Basin in Australia.