Coygan Cave, a Mousterian site on Carmarthen Bay northwest of the Gower Penninsula, contains a fauna accumulated primarily by hyaenas. The site was in a massive promontory called Coygan Rock that overlooked the coastal plain to the south. The artefacts consist mostly of Mousterian handaxes, few in number, suggesting that the site was not an important habitation. The fauna originally served as a type locality for the Middle Devensian (MIS 3) mammal age zone, but was subsequently replaced by the fauna from Pin Hole.
The cave was excavated five times, first by Hicks in 1866, then by Laws in 1888, then by Eccles and Dalton in 1913 and 1917, then by Grimes and Cowley in 1933 and 1935, and finally by McBurney and Clegg in 1963 and 1964. The cave was destroyed entirely by quarrying in the 1970s. The fauna presented here is from the excavations by McBurney and Clegg and is composed of animals collected from all layers throughout the cave. Aldhouse-Green et al. (1995) interpreted this as a single Devensian fauna that was largely assembled by hyaenas denning in the cave. Mousterian artefacts were found in situ in one of the middle units.