Whilst the original name is Tomaneena, renaming it ‘Turlough Hill' has a certain validity. The pumped storage station draws water from the mountain top lake, which thus becomes a ‘dry lake'. There is a geological feature known as a Turlough; it is defined as (in Ireland) a low-lying area on limestone which becomes flooded in wet weather through the welling up of groundwater from the rock. ORIGIN late 17th cent.: from Irish turloch, from tur ‘dry' + loch ‘lake'.