The first Hadesarchaea that people found were in a mine in South Africa about 3 km (2 mi) under the surface of the Earth. They do not need oxygen or light to live. They were later also found in the White Oak River estuary in North Carolina, a place where a river meets the ocean, and in Yellowstone National Park's Lower Culex Basin. These areas are hot, 70 °C (158 °F), and are so alkaline that they would destroy most living things. Other scientists looked through the soil near old mines in East Harz, Germany and think they may have found pieces of 16S rRNA that could be from Hadesarchaea or their close relatives.