Llyn Fawr

Llyn Fawr ('large lake' in Welsh) is a reservoir that occupies one of a series glacial cirques that form the northern escarpment of the South Wales Coalfield uplands, overlooking the heads of the Vale of Neath and the Cynon Valley [1]. It is known as the site of an important hoard of weapons and tools from the late Bronze Age and early Iron Age [1]. It lies on the northern flanks of Craig-y-Llyn [1]. Owing to its rapid and massive industrialisation during its coalfield boom, the Rhondda Valley, which lies on the south side of the escarpment, surpassed the supply of water it could source from its own river, so in 1909 the Water Works division of Rhondda Urban District Council contracted builders to convert Llyn Fawr into a reservoir [1]. Originally having an area of 11.927 acres, the lake was expanded, by the construction of a 25-foot high embankment dam and deepening of lake bed [1]. Bronze items included two cauldrons and axeheads [1]. The items appear to have been placed in the lake as votive offerings [1].