The Eastern Hills are collectively known as ‘Purvanchal’.
These hills running through the north-eastern states are mostly composed of strong sandstones which are sedimentary rocks. They are covered with dense forest, they mostly run as parallel ranges and valleys. Purvanchal comprises of the Mizo hills, Naga hills, Manipur hills, Patkai Bum, Garo, Khasi and Jaintia hills.