Widely dispersed, isolated finds of individual fossils of bone fragments (Atapuerca, Mauer mandible), stone artifacts or assemblages that suggest that during Lower Paleolithic, spanning from 3 million until 300,000 years ago, palaeo-human presence are rare and typically separated by thousands of years. The karstic region of the Atapuerca Mountains in Spain represents the currently earliest known and reliably dated location of residence for more than a single generation and a group of individuals. Prolonged presence has been attested for "Homo antecessor" (or "Homo erectus antecessor", "Homo heidelbergensis," and Neanderthals).