Overview
Three Rock Mountain (Irish: Sliabh na gCloch) dominates the southern fringe of Dublin at 444 m (1,479 ft) above sea level. Its name comes from three striking granite tors that crown the summit – natural weathered outcrops that were once mistaken for ancient altars. Today the tors sit beneath a cluster of radio masts, but the surrounding forest of Sitka spruce, Japanese larch, Scots pine, Monterey pine and lodge‑pole pine provides a tranquil backdrop for walkers, cyclists and history enthusiasts alike.
From the summit you can see Dublin Bay, the Howth Head peninsula, the Sugar Loaf, the Wicklow Mountains and, on a clear day, even the Welsh peaks of Snowdon and Cader Idris across the Irish Sea. The view has inspired writers for centuries; Weston St. John Joyce described it as “a commanding height” that stretches over sea, plain and mountain.
History
The three tors are natural granite formations created by millennia of weathering – they are not man‑made. The summit, however, holds a range of archaeological features. Four bowl‑shaped depressions – bullauns – date to early Christian times and were used for grinding or ritual purposes. Nearby lie the ruins of an army shooting range that operated until the 1970s, complete with a concrete dugout and a red warning flag. Scattered across the slopes are faint traces of hill forts, ring forts and 19th‑century quarry pits that supplied paving stone to Dublin. A small stone‑lined holy well, Grumley’s Well, reputed to cure eye ailments, sits close to the Ticknock road.
What to See & Do
Walking the Dublin Mountains Way
Three Rock is a key waypoint on the long‑distance Dublin Mountains Way. The trail links Shankill to Tallaght and passes the summit via a well‑marked yellow waymarker. A popular 8 km loop – often called the Two Rock & Three Rock Mountain Loop – starts at the Ticknock car‑park, climbs through mixed‑species forest, reaches the three tors, continues to Two Rock (the highest point on the Way at 536 m) and returns via the same track.
| Trail | Distance | Duration | Elevation gain |
|---|---|---|---|
| Two Rock & Three Rock Loop (Hika) | 8 km | ~3 h | 393 m |
The route is classified as moderate: expect some rocky sections, boardwalks and gentle scree. The forest offers occasional clearings where you can pause for a picnic while the city sprawls below.
Family‑friendly buggy walk
The Journal lists a 3 km, 1.5‑hour stroll that is stroller‑friendly and ideal for families with young children. The walk follows the paved forest road up to the metal barrier at the mast site, then a short detour to the three tors before looping back via a picnic area. The route is well‑signposted, has a gentle gradient and provides plenty of places to stop for a snack.
Mountain‑bike loops
For cyclists, the area hosts several marked loops. The Three Rock MTB Loop (29 km) starts on the slopes of Kilmashogue, summits both Two and Three Rock, and returns via forest tracks. Shorter options include the Three and Two Rock Loop (11 km) and the Three Rock – Loop Route 3 (24 km). All are graded moderate and provide a mix of gravel, forest road and occasional single‑track sections. Note that, following recent storm damage, some Ticknock MTB trails are temporarily closed – check the Dublin Mountains Partnership news page for the latest status.
Heritage spotting
- Bullauns on the central tor – early Christian grinding stones.
- Old army range ruins – concrete dugout and former target posts.
- Hill‑fort remnants hidden among the pines.
- Grumley’s Well – a small stone‑lined well reputed to aid eyesight.
- Quarry scars near the village of Barnacullia, a reminder of 19th‑century stone‑cutting.
Radio‑mast viewpoint
While the masts are functional, they make a striking silhouette against the sky. Photographers enjoy the contrast of modern steel against ancient rock, especially at sunrise or sunset.
Wildlife & Seasonal Highlights
The mixed‑species forest supports a variety of wildlife. Walkers often spot badgers, rabbits and a range of birds such as woodpeckers, tits and occasional raptors. In spring the forest floor is dotted with bluebells and the larch trees turn a golden hue, while autumn brings a carpet of amber leaves. Winter can bring strong winds and occasional snow; the car‑park may close temporarily under Met Éireann red‑wind warnings.
Cultural Activities
The Dublin Mountains Partnership runs a seasonal audio‑walk called “Ticknock: What’s Going On?” – a podcast that guides listeners through key sites including Three Rock, Fairy Castle and Two Rock, blending poetry and ambient sound. The project is part of the DLR Arts “Nature and Place” series, with installations by local artists that can be heard via the podcast (search “Ticknock: What’s Going On?” on your favourite platform).
Weather
The summit sits at 450 m; weather can change quickly. Typical summer temperatures are mild (max 15‑18 °C) while winter can bring sub‑zero nights and strong gusts. A quick check of the [Three Rock forecast](https://www.mountain-forecast.com/peaks/Three-Rock/forecasts/450) is recommended before heading out.
Practical Information
Getting there
The most convenient entry point is the Ticknock car‑park off the R113. The car‑park opens at 06:00 and closes at 22:00; it offers 145 spaces and is free of charge. From the city centre you can drive via the R113, or take the 44b bus (weekdays) to Ballinteer and walk a short distance to the forest entrance. The 44 bus runs every day and also serves the area. For those preferring rail, the DART to Shankill allows a 15‑minute walk to the start of the Dublin Mountains Way.
Trailheads & Parking
- Ticknock car‑park – primary start for the Two Rock & Three Rock loop.
- Kilmashogue recreation site – provides access to the the Wicklow Way segment that skirts the mountain’s western flank.
Facilities
There are no toilets on the site; visitors should use facilities in nearby Ballinteer or at the Ticknock visitor centre (if open). Bins are not provided – please take litter home. Dogs are permitted but must be kept under control and waste taken away.
Accessibility
Main forest roads are paved and suitable for children and visitors with limited mobility, though some sections of the walking loops involve uneven ground and moderate ascents.
Seasonal notes
The loop is open all year. In winter, snow or ice warnings may lead to temporary car‑park closure; check the Dublin Mountains news page for updates. The radio‑mast area can be windy, so be prepared for gusts if you plan to linger at the summit.
Safety
The radio‑mast site is fenced; stay on marked paths and respect any signage about restricted zones. While the trails are generally well‑maintained, sections near the summit can be slippery after rain.
Nearby attractions
- Fairy Castle on Two Rock – a cairn thought to cover a Neolithic passage tomb.
- The Scalp viewpoint further along the Dublin Mountains Way.
- Ticknock Forest – a 10 km network of walks, including the Fairy Castle Loop and the start of the Wicklow Way.
- Ballyboden – a suburban gateway to the Dublin Mountains.
- Carrickgollogan – another recreation site with historic ruins and woodland trails.