Limestone high quality quarried limestone, called Indiana limestone. Many famous buildings in London are built from Portland limestone. Limestone was also a very popular building block in the Middle Ages in the areas where it occurred, since it is hard, durable, and commonly occurs in easily accessible surface exposures. Many medieval churches and castles in Europe are made of limestone. Beer stone was a popular kind of limestone for medieval buildings in southern England. Limestone and (to a lesser extent) marble are reactive to acid solutions, making acid rain a significant problem to the preservation of artifacts made from this stone.
Stone Forest 270 million years ago. Extensive deposits of sandstone overlain by limestone accumulated in this basin during the Permian period of geologic time. Uplift of this region occurred subsequent to deposition. Later, exposure to wind and running water shaped these limestone pillars. These formations extend as far as the eye can see, looking like a vast forest of stone, hence the name "the Stone Forest". The Major and Minor Stone Forests are developed in the nearly pure limestone of the Permian Makou Formation. The Naigu Stone Forest, 9 km northeast of the Major Stone Forest, is developed in dolomite and dolomitic