The national park covers 2,067 hectares and contains spectacular natural rock formations. Mirima, also known as Hidden Valley, is an ancient limestone range that has been eroded over centuries by wind and the waters of Lily Creek into a broken series of gorges and twisted valleys. Spectacular rock formations in parts of the national park bear a resemblance to the more famous and larger Bungle Bungles in Purnululu National Park. Regarded as a site of special signifcance, Mirima is the name given to the area by the local Aboriginal people, the Miriwoong. Rock paintings and engravings have been found here, and at Lily Pool visitors can see indentations in the rocks where axes and spears were once sharpened.

Mirima National Park is less than 5 minutes drive from Kununurra, which is a 3 hour flight north east of Perth. By road it is a 33 hour drive.