Pollution in the air causes acid rain. And limestone is a calcium carbonate compound, which is an alkali. So when an acid and alkali mixes together, you get a reaction. Which is dissolution. Dissolutions causes the outside layer to dissolve, resulting in mush.
Mediterranean climate, major climate type of the Köppen classification characterized by hot, dry summers and cool, wet winters and located between about 30° and 45° latitude north and south of the Equator and on the western sides of the continents.
