The Blue and John Crow Mountains National Park conserves about 78,000 hectares (200,000 acres) of tropical rain-forest in the north-east of Jamaica. These forests cover the steep mountain slopes (mostly over 3,000 feet) in the interior of the parishes of St. Andrew, Portland, St. Thomas and St. Mary. The geology of the Blue Mountains is shale, whilst that of the John Crow Mountains further to the east is limestone. Both mountain ranges are unique in the island due to their geology, elevation, and rainfall. The forests of the Blue and John Crow Mountains National Park are world renowned for their biological diversity and many researchers come to explore and study the area. The lush forests house a wealth of natural resources that are appreciated best for their intrinsic value and for maintaining certain essential ecological processes.