Local people in Ballinafunshoge and the neighbouring townland of Cullentragh Park have long called this stretch of ground Lo Darrig, a name the scholar Liam Price recorded in 1945 and interpreted as log dearg, meaning roughly "red hollow" or "red depression". In the Wicklow mountains, the word log has shifted in usage over time and is now commonly applied to upland features more broadly, as seen in nearby mountain names such as Lugnaquillia and Lugduff. That the word should carry a colour, and that colour red, hints at what local tradition says happened here.

According to that tradition, this is where the Battle of Glenmalure was fought in August 1580, one of the more consequential encounters of the Elizabethan campaigns in Ireland. An English force under Lord Grey de Wilton marched into the glen to suppress the Wicklow chieftain Fiach Mac Hugh O'Byrne and was routed in the confined, heavily wooded terrain. Among those killed was Francis Cosby, a figure well known in the military administration of the Pale. The defeat was significant enough to reverberate in English colonial policy and to lodge itself in Gaelic memory as a rare and clear victory. Price was careful to note that the placename Lo Darrig belongs to a specific topographical feature, a flat grassy area at the top of the glen side, and that its coordinates should be read only as an approximate guide to where the name sits on the landscape, not as a precise marker of where the fighting took place.