Devil's Marbles, also known as Karlu Karlu in the local Aboriginal language, is a geological phenomenon located in the Northern Territory of Australia. It is a collection of large, rounded granite boulders scattered across a vast plain. The rocks are thought to have been formed by the process of weathering, erosion, and expansion and contraction of the rock due to changes in temperature.

The rocks are considered a significant spiritual and cultural site by the local Warumungu, Kaytetye, Alyawarra and Warlpiri peoples, who believe that they were formed during the Dreamtime by ancestral beings. The site is a popular tourist destination and offers visitors the opportunity to explore the rocks, walk around the surrounding desert, and learn about the cultural significance of the site through guided tours and interpretive signage.

In addition to their cultural and spiritual significance, the Devil's Marbles are also a unique geological feature, attracting geologists and scientists from around the world who are interested in studying the formation and composition of the rocks. The site is also home to a range of flora and fauna, including several species of reptiles, birds, and mammals, such as wallabies and dingoes.