Another story which I'm hoping applies to this stone. You get a lot packed in - fairies, Finn McCool, special tree species and petrification.
In a field at Balcunnin two miles from Skerries, there is a tall stone shaped somewhat like a man. It is said that a fairy queen was going to Fionn Mac Cumhail when a man leapt out of a hedge and tried to seize her. Like magic a hazel rod appeared in her hand and she turned her man into a rock.
From the Schools Collection of the 1930s, now being transcribed at Duchas.ie.
There is a very large stone called the "Ho or Howe Stone" in a field near Balcunnin cross roads. One going along the main road from Lusk to Skerries can view the "Ho stone" in the field on the right hand side of the road. It is only a distance of twenty yards from the Balcunnin Cross Roads. It is about five feet in height and must weigh about 3 or 4 tons in weight. There is a smaller stone near it but whether this was broken from the original stone would be difficult to state. The "Ho stone" resembles Cromlech stones which are to be seen in many parts of Ireland but there is no visible inscription on it.
Some say that it was part of Baldungan Castle that was destroyed in the rebellion of war but this would belie the suggestion that castle was destroyed by Cromwell from the sea and it is situated on the same road as Cromwell's Bush. If Cromwell destroyed Baldungan Castle from Loughshinny by cannon fire it is very unlikely that a mass of stone weighing some tons could be blown for such a distance as it lies almost a half mile from the site of the castle.
Local tradition states that it covers the entrance to a cave or a passage which leads to Baldungan Castle but no effort has ever been made to prove this assertion. The defenders of the Castle are supposed to have retreated into this passage with their valuables and when the Castle was levelled the passage is supposed to have caved in on them. There seems to be no entrance from Baldungan Castle at present to this supposed passage but the entrance may have been choked by falling debris which still remains concealing the entrance.
No no don't overthink the folklore please, you're trying to hard to make it make sense. It's not necessary. A story in the 1930s Schools Collection which is now being digitised at duchas.ie.