Small lake in a rocky portion of the island of Anglesey, northwestern Wales, once the centre of ritual activity in the late Iron Age. Twentieth-century excavations at Llyn Cerrig Bach, especially at the edge of a bog under an 11-foot sheer rock cliff, have revealed an enormous trove of uncorroded metal objects. Evidently thrown off the cliff over as much as 200 years, c. 2nd cent. bc–1st cent. ad, the objects include cauldrons, chariots, harness and other fittings, musical instruments, chains for slave gangs, and ironworkers', tools. Most items appear well made as if possessions of the most privileged classes; some appear deliberately damaged before having been thrown in the lake. Unfounded speculation has suggested the objects may have been thrown by the druids that Tacitus tells of being slaughtered in ad 61.
See Cyril Fox, A Find of the Early Iron Age from Llyn Cerrig Bach, Anglesey (Cardiff, 1946);P. Lynch, Prehistoric Anglesey (Anglesey, 1970), 249–77.