Based on these observations, an initial hypothesis was formed which states that the visibility of the locations into which cave sites are carved increases over time.

Only 33% of prominent sites are visible from an ancient settlement in the pre-Tang sample, and 86% in the Tang. As Buddhism did not arrive in all areas of China at the same time, the sites were also, for the purposes of this article, divided into early and late for their region. In the north, the early phase is the Northern and Southern Dynasties, and the later phase is the Tang; in the south, the early phase is the High and Middle Tang, and the later phase is Late Tang. This makes the variations clearer, with 37% of sites in the early period in non-visible locations, compared to 0% in the late period.

As Buddhism became more established in China, its temples became increasingly prominent.