Tonelagee

About Tonelagee

Rising as the third-highest peak in the Wicklow Mountains, this massive granite dome offers a classic Irish upland experience. Characterised by expansive peat hags and a broad summit plateau, it is most famous for the spectacular view down to the perfectly heart-shaped Lough Ouler nestled in the corrie beneath its northern slopes.

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Did You Know?

• •The name Tonelagee is an anglicisation of the Irish 'Tóin le Gaoith', which translates literally to 'Back to the Wind'. This refers to the mountain's exposed position, where the summit plateau is famously vulnerable to the prevailing westerlies blowing across the central Wicklow range.
• •Below the northern cliffs lies Lough Ouler, a natural glacial lake that forms a near-perfect heart shape when viewed from the summit ridge. It is widely considered one of the most striking geological features in the Republic of Ireland.
• •The summit offers a clear sightline to Turlough Hill to the south, home to Ireland's only pumped-storage hydroelectric station. The artificial upper reservoir provides a sharp geometric contrast to the wild, rounded profile of the neighbouring Mullaghcleevaun.
• •As the third-highest mountain in Wicklow after Lugnaquilla and Mullaghcleevaun, it serves as a crucial navigational waypoint for those attempting the 'Wicklow Round', a 100km long-distance challenge taking in 26 peaks.
• •While the view of the heart-shaped lake is romantic, the actual ground underfoot is less so; the approach from the Wicklow Gap involves a persistent battle with 'black hags'—eroded peat channels that can swallow a hiking boot whole in wet weather.