This west Wicklow summit can be visited itself for a short up and down walk or will fit into various longer walks. One way of ascending is from around the car park at N9343 0239 A on the minor road there. Start on a track directly up from there. It is possible to reach it from the east from around N9804 0038 B taking in Corriebracks. Plan your route carefully through the forestry.
The summit has a number of ruins on top. Linkback: https://mountainviews.ie/summit/367/comment/5126/

Returning recently to Church Mountain – or Sliabh Gad(oe), or Sliabh an Chodaigh, as it is variously called – I was as intrigued as ever by the size of the cairn on top and its metamorphosis in later times. This finally prompted me to do a little armchair exploration.

The prehistoric cairn is approximately 25m in diameter and stands 3m high at its most elevated point today. In Christian times, the centre was hollowed out and a little church was built inside. In itself, this is hardly surprising, since it would correspond to the common early Christian practice of ‘baptising’ pagan cultic sites. In the specific case of Church Mountain, historical speculation has been carried a little further. It is known that Palladius, St. Patrick’s less successful predecessor in bringing Christianity to Ireland, came to West Wicklow around 431 AD and established a church there, his second, at a place called ‘Domnacha Arda’. Might not this be the origin of the placename Donard (rather than Dún Ard, as others suggest)? Translated as ‘the church of the high field’, this placename would indicate that Palladius’ chapel was located, not in today’s Donard village, but on the nearby (Church) mountain, atop the cairn or passage grave that was there. Although the vestiges of the church that are visible today – a scant 9 x 6m rectangular outline – are from a later period and dated to the 12th century, it would be reasonable to think that the more recent church will have replaced others, going back to an early Christian structure. One thing, at least, is certain: there has been a long-standing tradition of Christian pilgrimage linked to the mountain. George Petrie, “the father of Irish archaeology”, wrote in 1808 that every year, on Lammas Day (1st August), hundreds of people would ascend the mountain on their knees and a priest recite prayers from the altar, but the practice had ceased after the 1798 rebellion. His friend, the professor of antiquities G. N. Wright, speaks in his “Guide to the County of Wicklow” (1827) of the ruins of a chapel on the summit “where numbers of pilgrims and penitents are constantly to be found, engaged in acts of devotion” and also mentions a holy well, close to the ruined walls, “whose surface is only two feet below the highest point of the mountain, and the spring continues to flow the whole year without much increase or diminution; the water has rather an unpleasant, astringent taste, resembling bog-water, although it is perfectly clear” (p.166).

You will look in vain today for pagan spectres or Christian pilgrims on Church Mountain. Personally, I have never met any. They have been replaced by the serried ranks of drab commercial forestry, marching up on all sides. As I saw on my last visit, even the ultimate indignity of quad biking has not been spared the mountain. It is anyone’s guess if it will be allowed to retain into the future a remnant of the character that made it so special in the past. Linkback: https://mountainviews.ie/summit/367/comment/3346/

I recently hiked Church Mountain with my wife and daughter - it was a nice family day out for Mothers Day! We came from Dublin and took a nice drive through the Hollywood Glen, before turning left at Hell Kettle Br.
At the end of the laneway where the track begins you end up in farmyard with several farm buidings and farmhouse (OS sheet 56, GR S946 993 C). For anyone planning approaching the hill from here, it's a good idea to check with the farmer if it's ok to park there, as it's a bit tight for space. We did, and found him to be a very friendly and helpful gent.
As mentioned by csd in his comment, the forestry plantation is now much more extensive than marked on the map, currently extending to approx. GR S953 999 D on the map. Here a track runs uphill due west along the perimeter fence of the forestry plantation, before turning due north, again staying along the border of the forestry, at approx. GR S951 999 E, and then runs along the ridge that runs north/south along the spine of the mountain (there's a conveniently placed bench at this point if you're out of breath from the steep hike from the main track!).
From here it's a gentle ascent along a dead straight track until near the summit. As you approach the summit the terrain flattens a little, and it may be tempting to leave the track and head accross the heather to find the cairn and triangulation pillar. Dont!! There's a much easier way. Keey your eyes open for the stones arranged in the shape of a cross on your right, at the edge of the forestry fence (it's beside a fence post which is supported by a couple of large rocks). The bottom point of the cross points roughly NW - let your eye follow this direction, and you will see the old eroded trail which leads directly to the summit.
Beside the extensive Cairn, atop of which sits the trig. pillar, there's a lovely stone bench erected in memory of a local man. Nice to take a seat and take in the view NE. If you need a more sheltered place to sit, on the SW side of the Cairn there's a stone enclosure with some flat rocks ideal for sitting out of the wind and enjoying that well deserved cup of tea! Cheers! Linkback: https://mountainviews.ie/summit/367/comment/3698/

Church Mountain offers some great views over west Wicklow and the southern Wicklow Mountains. If coming from Corriebracks, access to the summit can be gained by way of an eroded track that runs up the firebreak on the eastern slopes. The conifer plantation is now much more extensive than shown on Sheet 56, covering most of the eastern side of the mountain. There are a trig pillar and the remains of a prehistoric cairn at the summit (see pic). Linkback: https://mountainviews.ie/summit/367/comment/561/

Trig. Pillar on Church Mt. with Blessington Lakes in background. Oct 2003. Linkback: https://mountainviews.ie/summit/367/comment/731/