The valley was carved by a cirque glacier during the last Ice Age, creating its distinct horseshoe shape.
The cliffs contain 'Diarmuid and Gráinne’s Cave,' associated with the Irish mythological tale of the lovers' flight from Fionn mac Cumhaill.
Barytes was mined in the area during the 19th and early 20th centuries, with remnants of industrial activity still visible.
The Truskmore mountain peak at the head of the valley serves as a site for a major television and radio transmitter mast.
The limestone cliffs are home to rare alpine flora adapted to the nutrient-poor, rocky environment.
The Gleniff Horseshoe is a dramatic, U-shaped glacial valley located in the Dartry Mountains of County Sligo. The valley is defined by high limestone cliffs, including the 300-meter-high sheer rock face of Truskmore. A narrow, 10-kilometer public road loops through the base of the horseshoe, providing a circuit for motorists, cyclists, and walkers. The landscape is characterized by steep scree slopes, exposed rock formations, and traditional upland farmland. The area is geologically significant for its karst topography and cave systems. Access to the interior of the valley is largely through private agricultural lands, requiring adherence to local access protocols.
From the base of the valley looking upward at the converging cliff faces as you complete the loop.
Drive or cycle the loop in a clockwise direction for optimal views of the cliffs.
Ensure your vehicle is capable of navigating narrow, single-lane rural roads with passing places.
Respect all 'No Trespassing' signs as the valley floor is primarily active farmland with grazing livestock.
Attempting to climb the steep scree slopes without mountaineering experience or proper gear, as they are prone to rockfall.
Wear sturdy, waterproof hiking boots if leaving the road; close all gates behind you and do not disturb livestock.
