The first is Croghan Hill which is on here (I think you added that site). The other is a tumulus at Forelacka which 19.2m in diameter. Forelacka is somewhere near Kinnity, the OS reference is N208 032. I haven't been to either of these sites but I'm hoping to get to Forelacka soon enough since it's around the corner from me. I have also read that Forelacka has evidence of kerbing and may be a passage tomb....the archaeological inventory has none of this information.