It is located about 10 km (6 mi) east of Ballyhaunis, just north of the village of Ballinlough and is the source of the River Suck.

[1] There is an artificial island known as a crannog in the lake; this is believed to date back to the Medieval period, when it would have been used as a place of safety to retreat to when under attack.

[5] Fish species in Lough O'Flynn include roach, perch, brown trout, pike and the critically endangered European eel.

Active raised bogs have a high percentage of sphagnum moss and new peat is being formed; in this case, there are hummocks and extensive quaking areas and many large steep-sided pools intersecting with each other.

On more degraded parts where peat removal has happened in the past, heather, bog asphodel, hare’s-tail cottongrass, deergrass and cross-leaved heath are to be found.