Among the small islands scattered across its surface is one known as Otter Island, a place that carries an archaeological designation but whose recorded history remains, for the moment, largely unspoken in any public form.

The lake itself has deep connections to Irish cultural life. The novelist George Moore grew up at Moore Hall on its eastern shore, and the surrounding landscape figures in accounts of both prehistoric settlement and early Christian activity in the region. Lough Carra's islands, like those of many Irish lakes, were attractive to early communities precisely because water offered a natural form of defence. Some such islands were artificially constructed or enlarged as crannogs, lake dwellings built on timber platforms or accumulated debris, used from the Bronze Age through to the early modern period. Whether Otter Island belongs to that tradition, or holds the traces of some other kind of human presence, is a question the available record does not yet answer in full.