Devil's Lair is a single-chamber cave with a floor area of around 200 m² (2,200 sq ft) that formed in a Quaternary dune limestone of the Leeuwin–Naturaliste Ridge, 5 km (3.1 mi) from the modern coastline of Western Australia. The stratigraphic sequence in the cave floor deposit consists of 660 cm (260 in) of sandy sediments, with more than 100 distinct layers, intercalated with flowstone and other indurated deposits. Excavations have been made in several areas of the cave floor. Since 1973, excavations have been concentrated in the middle (approximately on a north-west, south-east axis) of the cave, where 10 trenches have been dug. Archaeological evidence for intermittent human occupation extends down about 350 cm (140 in) to layer 30, with hearths, bone, and stone artefacts found throughout. The site provides evidence of human habitation of Southwest Australia 50,000 years before the present day.