Around 360 million years ago during the Carboniferous period, England was lying at the equator, covered by the warm shallow waters of the Rheic Ocean. During this time Carboniferous Limestone was deposited, as found in the Mendip Hills, in the Peak District of Derbyshire, north Lancashire and the northern Pennines. The erosion of this landscape by carbonation has led to very distinctive scenery. Particularly notable is the area around Malham in the Yorkshire Dales with its limestone pavements, sink holes and shake holes. Gaping Gill contains a waterfall disappearing underground into the Carboniferous limestone.