[RWD version 1 ] The Bluestacks Aghlas can be reached as others have shown from a road leaving the R250 at the SW end of Lough Finn. There is parking there on waste ground. There is a GAA sports ground nearby.
Follow this road as it trends SE. We asked permission at the far end of the road and were assured it was ok however it is always wise to check with anyone you may see.
Leave the road via a gate and start climbing the extremely steep slope upwards. The route we took seemed to work fine however others have taken variant routes.
Unfortunately the weather on the day we did it was a trifle moist however we reached both tops and then decided to head NE along somewhat less steep slopes arriving on a track above the lake. We then returned via the forest road to the start.
There are various possibilities for a longer walk around here. To the NE of Aghla Mtn is Scraigs. While not as high at 428m it shares the same steep cliffs to the NW facing Lough Finn as Aghla has. Combined as a linear walk this could make a fine walk.