|| Ingleborough is the second highest mountain in the Yorkshire Dales with a height of 723 m ( 2373 ft ) . It is one of the Yorkshire Three Peaks , the other two being Whernside and Pen y ghent . Ingleborough is frequently climbed as part of the Three Peaks Challenge , which is a 24 mile ( 38 km ) circular challenge walk starting and finishing in Horton in Ribblesdale . A limestone pavement is a natural karst landform consisting of a flat , incised surface of exposed limestone that resembles an artificial pavement . Conditions for limestone pavements are created when an advancing glacier scrapes away overburden and exposes horizontally bedded limestone , with subsequent glacial retreat leaving behind a flat , bare surface . Limestone is slightly soluble in water , so corrosive drainage along joints and cracks in the limestone can produce slabs called " clints " isolated by deep fissures called " grikes " or " grykes " . ?