Coolderry is a townland, this one in Magheracloone civil parish, in the extreme southern end of the parish, just east of where Co. Louth and Co. Meath meet the Co. Monaghan border. Coolderry, Magheracloone, Monaghan is right on the Monaghan/Louth border. It is right next to Magheracloone's Killark townland, to its northeast. A little tip of Killark also meets the Louth border, beyond an intervening cluster of four townlands east of Coolderry. Both townlands are south of Carrickmacross, and closer to and southeast of, Carrickashedoge. Hope this helps. Sally M