Two Rock Mountain has a pre-historic cairn known as "Fairy Castle" marking it's summit. There are panoramic views from the top which include Mullacleevaun, Tonlegee, the Sugarloaf , Cooleys and Mournes as well as interesting views of Dublin City and the East Coast.

It's a focal point for for many walks including "Sunday afternoon strolls" and longer walks which might incorporate parts of the Wicklow Way (From Marlay Park to Cloneygal in Carlow) or the newer Dublin Mountains Way( From Tallaght to Shankhill). The development work for these trails has helped to contain the significant erosion at the top.

It's an easily accessible mountain, some of the more popular routes would be from Tibraddan Car Park (O1380 2284 A) or Glencullen (O1910 2060 B), using the DMW. From Marlay Park or Kilmashogue Car Park (O1520 2440 C) using the Wicklow Way. From the East side, starting at the Blue Light Pub (O1809 2413 D) and walking via Three Rock Mountain or, starting at Kilgobbin Cemetary (O1891 2438 E), for a longer walk using the old mass path from Barnacullia to Sandyford Church .. see track 800.

Tracks 800 and 852 include this mountain Linkback: https://mountainviews.ie/summit/382/comment/5141/

I have read that the name ‘Two Rock’ does not appear before the 19th century. In earlier maps, it seems, the place is referred to as ‘Black Mountain’, which, to my mind, is a perfect description of the mire that walkers have to trudge through on some of the approaches. The highest point on Two Rock is marked, of course, by the pre-historic cairn known as ‘Fairy Castle’ (O 1721 2238 F), on top of which a more recent pyramid or cone of rocks continues to grow at the whim of latter-day Flintstones. The original cairn underneath stands almost 3m high today, though it would be logical to think it has shrunk over the centuries through subsidence and erosion. I have seen reference to the remains of a kerb around the outer edge of the cairn, of which twenty-two stones are supposedly still in position, but today’s cloak of earth and vegetation makes it rather difficult to verify that. I am surprised to find no reference to any excavation of the cairn, especially since it has been surmised that it may contain a chamber similar to the one on Seefin. What strikes me most about this somewhat bleak though splendidly panoramic mountain is the fact that there are so many other prehistoric monuments on all sides. There is a burial cairn on Tibradden, a wedge tomb at Kilmashogue, and another at Ballyedmonduff, all within a short walk. It shows that from the late Stone Age onwards there were well-organised social communities living close to this mountain and climbing it like ourselves, though not, I suppose, with the same recreational intentions.

The photo was taken from on top of the 'cone' on Fairy Castle, looking southwards along the dark shoulder of Two Rock. On the horizon is the triangle of the Great Sugar Loaf and the distinctive saddle of the Little Sugar Loaf. Linkback: https://mountainviews.ie/summit/382/comment/3376/

As mentioned by murphysw, the Kilmashogue forest car park is a good starting point for this walk. I followed this path all the way to the masts at Three Rock Mountain and I would recommend it as the views of Dublin City from here are second to none. From here there is an obvious trail heading South up to the cairn and trig on top of Fairy Castle with great views over to the Wicklow Mountains. From here follow the trail South West for about 500 metres before coming to a junction where the trail forks. Take the route to the right which will bring you back to the main Coilte road from the start of the walk. Follow this for about two kilometers and you will be back at the car park. The route is just over 9km if you find yourself near the capital with a couple of hours to spare and the weather allows for it, I would highly recommend. Linkback: https://mountainviews.ie/summit/382/comment/20450/

Parked the car in the Kilmashogue car park for an evening stroll to the summit. The Wicklow Way leads up a very clear and wide path until it disappears up to the right through the forest near the summit. I decided to continue straight as judging by the paths on the OS map it looked quicker. Dont bother! It just leads out to a tarmac road which takes you by the array of tv masts on your way to the summit. The summit itself gives you great views of dublin and over towards Kippure (pity I left the camera in the glovebox). Descended by the path to the Wicklow Way, and down the Way itself. Disconcertingly the path ends in a dead end at the forest. If you retrace your steps a few yards you will see a tree marked with a white X. Enter the forest here and it is only a very short distance back to the path. The picture i've added here was taken on a different stroll to the summit, on a bright, clear autumn day. The picture I've added was taken on a different climb, on a bright, clear, autumn day. Linkback: https://mountainviews.ie/summit/382/comment/1869/