Logh Boderg is a large lough with a surface area of about 1,200 hectares (3,000 acres) which is on the River Shannon,[2] between Kilmore, County Roscommon and Annaduff in County Leitrim.

The mermaid predicted that if the people put her back in the water, in the eve of May day, which was soon, that they would be generously repaid one year later.

[5] Túathal Techtmar used Lough Boderg as one of the traditional boundaries of the ancient Kingdom of Meath: "From Loch-Bo-Deirg to Birra [Birr], From Sena [Shannon] eastward to the sea.

"[6] Lough Boderg is a noted fishery for bream, rudd, roach, northern pike, eel and perch.

[2] The North Shannon Motor Yacht Club is based on Lough Boderg.