Retaining walls are generally installed in gardens and across landscapes to keep the soil in place and to create level terraces on which to garden. Slopes, even very steep ones, can employ retaining walls of stone or wood to transform a difficult gardening situation into a prime focal point of the garden.

Retaining walls need to be strong - strong enough to maintain the earth and water in their hold, so the building of such features is generally subject to stringent building code in most areas.