I think there's at least one more pair of souterrain+fort in Meenymore other than this one, so the folklore could refer to any of them. But I have added this one as it remains unplanted amongst the coniferous wood and might be more accessible.
There is an old fairy fort in the townland of Slievenard. There are lights seen at it often. One night people were coming home from a bottle drink in Pat McPartlins and they saw three little fairies outside of it dancing and singing for all they were worth. They were dressed in different colours. The people went down to see would they catch them but when they went to the place they were gone.
Another day two men went to cut bushes in it for fire wood but when they were cutting the bushes they heard several little voices saying leave them alone or ye will die and they left them alone and no one went near them since.
From an entry in the 1930s Schools Collection, which was made by the National Folklore Collection in the 1930s.