The Cappadocia region of Central Anatolia is characterized by fairy chimneys. They are formed within ash-flow tuffs. Some of the fairy chimneys were dwelled and contain invaluable wall paintings. Weathering and erosion, however, are still active and the chimneys are undergoing chemical and physical deterioration due to atmospheric effects. In order to understand the mechanisms of deterioration of the tuff, various physico-mechanical properties as well as pore-size distribution characteristics of the tuff before and after the accelerated weathering tests (wetting-drying, freezing-thawing and salt crystallization) are investigated. They are used to predict the durability of the tuff for the conservation purposes. Although the durability equations based on mercury porosimetry give high durability, the durability equations based on physico-mechanical properties, the accelerated weathering tests and the field observations yield poor durability. Therefore, there is a need to revise the durability equations based on the pore-size distribution for tuffs.