Stone retaining walls can be seen around the world, ranging from the ancient Roman structures that still snake their way across Europe to the colonial walls remaining in parts of Africa. At the most primitive level they are pieces of stone hauled out of the earth and stacked together so that the weight of the stones hold them in place -- and in the right conditions they will last indefinitely.
Just as durable as the ancient walls of stone are mortared walls. Cement is a building material that has been in use by humans for centuries. Today it is one of the primary building components used around the world for everything from house foundations to sidewalks and the streets you drive your car on. Once it is cured and hardened together with natural stone you have a retaining wall that will last for generations.
Type of Soil
The area where you live determines the durability of a wall. The softness of the soil, for example, will cause a wall to sink over the years until a compacted state has been reached, and if the wall does not sink across its length in the same fashion, you will have high and low spots. Sometimes these low spots are weakened by the slump and will sag outward. This is a process that takes years and is impossible to predict with complete accuracy because it has so many variables.
Similar to how where you live affects the compression of the wall, the freeze and thaw cycle can also cause problems within a wall. When water freezes, it expands, and this process can sometimes force walls to bulge upward in areas where the ground has buckled under the pressure of frozen water. As with soil compression, it takes years for the thaw cycle to affect a wall, and most of the time the effects simply spread throughout the length of a wall.