There are multiple synonyms for the term "rock cities," which refer to cities that are built on rocky terrain. Some of the synonyms include Cliff Cities, Stone Cities, Rock Metropolis, and Hilltop Cities. These terms mostly refer to ancient cities that were built on hills, cliffs, or rocky outcroppings to provide natural defense from enemies and natural disasters. Many of these cities were also built close to water sources, such as rivers or wells, to provide the necessary resources for the population. Some examples of famous rock cities include Petra in Jordan, Machu Picchu in Peru, and Sigiriya in Sri Lanka.