wiki tells us;
St. John's Eve (or Oiche Fheile Eoin (Bonfire Night)) is celebrated in many parts of rural Ireland with the lighting of bonfires. This ancient custom has its roots in pre-Christian Irish society when the Celts honored the Goddess Áine, the Celtic equivalent of Venus and Aphrodite. She was the Goddess Queen of Munster and Christianised rituals in her honour (as Naomh Áine) took place until the nineteenth century on Knockainy, (Cnoc Áine - the Hill of Áine) in County Limerick.
There for ye now.
St. John's Eve (or Oiche Fheile Eoin (Bonfire Night)) is celebrated in many parts of rural Ireland with the lighting of bonfires. This ancient custom has its roots in pre-Christian Irish society when the Celts honored the Goddess Áine, the Celtic equivalent of Venus and Aphrodite. She was the Goddess Queen of Munster and Christianised rituals in her honour (as Naomh Áine) took place until the nineteenth century on Knockainy, (Cnoc Áine - the Hill of Áine) in County Limerick.
There for ye now.