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.
Paulina's limestone rat Paulina's limestone rat Paulina's limestone rat ("Saxatilomys paulinae") is a genus of murid rodent native to central Laos and Vietnam. It was first discovered in the Khammouan Limestone National Biodiversity Conservation Area in Khammouan Province, Laos, and also been found in the Vietnamese province of Quang Bình. It is the only known species in the genus Saxatilomys. The genus name is derived from the Latin "saxatilis", meaning "among the rocks" and the Greek "mys", meaning mouse or rat. It resembles, and is likely closely related to, species in the genera "Niviventer" and "Chiromyscus". "Saxatilomys" is distinguished from these and other