As cultural changes occurred, particularly during the Pueblo III period between 1150 and 1300, kivas continued to have a prominent place in the community. However, some kivas were built above ground. Kiva architecture became more elaborate, with tower kivas and great kivas incorporating specialized floor features. For example, kivas found in Mesa Verde National Park were generally keyhole-shaped. In most larger communities, it was normal to find one kiva for each five or six rooms. Kiva destruction, primarily by burning, has been seen as a strong archaeological indicator of conflict and warfare among people of the South-West during this period.