Meghalaya - meaning the 'abode of the clouds' - is a state in the North East of India. It is a mountainous state comprising of the Khasi hills in the centre, the Jaintia hills in the east and the Garo hills in the west. The altitudes range between 150m to 2000m above sea level. The terrain is geologically rich and contains deposits of coal, limestone and uranium. With average rainfall as high as 12000mm in some places, Meghalaya is the wettest place on earth. Consequently, Meghalaya has some of the highest waterfalls in the country. Also, about 500 natural limestone and sandstone caves are spread over the entire state, including some of the longest and deepest caves in the sub-continent.