Three Rock Mountain

Three Rock Mountain (Irish: Binn Trí Charraig; archaic: Sliabh Ruadh) is a mountain in County Dublin, Ireland. It is 444 metres (1,457 feet) high and forms part of the group of hills in the Dublin Mountains which comprises Two Rock, Three Rock, Kilmashogue and Tibradden mountains.

The mountain takes its name from the three groups of granite rocks at the summit. It was once believed that these features were man-made: for instance, Gabriel Beranger wrote of them in 1780, "I take them to be altars upon which sacrifices were offered […] the regularity which is observed in piling them convinces me they are the work of man, as they could not grow in that position". In fact, the three outcrops are tors: natural geological features produced by the gradual process of weathering.

Today, the summit is dominated by the many radio masts and towers that use the site to broadcast their signals across the Dublin area below. The forestry plantations on the slopes consist mainly of Sitka spruce, Japanese larch, Scots pine, Monterey pine and lodgepole pine.

The views from the summit are extensive and have attracted visitors for many years. The writer Weston St. John Joyce described the vista thus: "The view from this commanding height, 1,479 feet over sea-level, extends over a vast tract of mountain, sea, and plain, comprising, to the north, the blue waters of Dublin Bay, with Clontarf and Howth, the Naul or Man-of-War hills, and the Mourne Mountains; eastward, Kingstown, Dalkey, and Killiney, and then in succession the fertile vale of Shanganagh, Carrickgollogan, the Scalp, Bray Head, the Sugar Loaves, and the slopes of Prince William's Seat. In clear weather Holyhead and the Welsh mountains may frequently be discerned, Snowdon and the Llanberis Pass being usually the most conspicuous, but occasionally the elongated outline of Cader Idris may be observed some distance to the right". By way of contrast, Gabriel Beranger said of Three Rock, "The extensive summit of this mountain, the parched ground and its solitude, make it the most awful spot I had ever seen".

Access to the mountain is possible via the Coillte-owned forest recreation areas of Ticknock and Kilmashogue. The route via Kilmashogue follows the Wicklow Way hiking trail for part of the way. Three Rock is also traversed by the Dublin Mountains Way hiking trail that runs between Shankill and Tallaght. In 2007 a concept was submitted to Dún Laoghaire–Rathdown County Council to create a cableway from the Sandyford Luas stop to Three Rock Mountain and to open up the views to touristic and easier access.

Several local sports clubs take their name from the mountain such as the Three Rock Orienteering Club has mapped the area and run orienteering competitions there since 1981 as well as Three Rock Rovers Hockey Club (field hockey) and Three Rock Rovers association football club.^{[citation needed]}

On the top of the central tor at the summit are four bowl-shaped depressions: these are bullauns which were used in early Christian times for grinding. At one time, to the east of central tor was the remains of an abandoned public house.

Close to the summit is the ruins of an old army shooting range which closed in the 1970s. The targets were raised and lowered by 12 men using levers in a concrete dugout. A red flag was raised along the forest road to alert visitors that firing exercises were in progress.