Carrowmore Lake is situated in the parishes of Kiltane and Kilcommon Erris, County Mayo between the villages of Bangor Erris and Barnatra at the southern end of Broadhaven Bay. The freshwater lake is over four miles long and almost 3 miles wide at its widest point.  Glencullen townlands line its eastern shore and Rathmorgan and the Knocknascollop mountains rise up along its western shores. Carrowmore is not a deep lake and it provides the drinking water for the whole of the Erris area. It is fed by the Carrowmore River and drains into the Owenmore River on its way to Blacksod Bay, The lake is designated as a S.P.A. (Birds directive) in E.U. law and also as 000476 Complex S.A.C. (Special Area of Conservation) It is an oligotrophic/mesotrophic lake with a substrate of Dalradian schists and pale quartzite. Its shorelines are dominated by blanket bog mainly but there are many houses, mainly linear in layout, along both sides of its shores. Its catchment area includes the townland of Bellanaboy in Kilcommon where the contentious Corrib Gas refinery is situated.