Geograph - photograph every grid square

The island of Staffa is made from three layers of rock covered with a surface of rich soil and lush grass. The lowest layer is tuff, compressed volcanic ash and dust, underneath columns of a black fine-grained Tertiary basalt, over which is a third layer of basaltic lava without a crystalline structure. The effect of the basalt columns is very noticeable at the southern end of the island where a causeway links the landing stage at Clamshell Cave with An Uaimh Bhinn(Cave of Melody) or, as it is more commonly known, Fingal's Cave.