An aoul (derrived from Tatar language awıl) is a type of fortified village found throughout the Caucasus mountains, especially in Dagestan. They are generally built out of stone on faces of ridges or against cliffs to guard against surprise attacks. Houses are usually two stories high, and they were staggered to make it virtually impossible for enemies to get anywhere on the roads. The houses usually have a southern aspect to take advantage of the sun in the winter and to be shelthered from the northern winds. Often, they are not located near good farmland or water sources, so it is necessary to bring water into the settlement.

In the 19th century, as Russia fought to conquer the Caucasus, aouls were very formidable defenses and could be taken pretty much only by storming.