Does anyone here know anything about the Midsummer celebrations in England or Ireland? Also, if anyone knows anything about Irish fairy lore, that could be potentially helpful as well.
If you're talking about midsummer celebrations in the present, they're not around in the mainstream any more, in the UK at least. I don't know about Ireland, though.
On the other hand, if you're looking for past events, there's a few bits and pieces of info on Wikipedia. Here are the links:
We shall not cease from exploration, and the end of all our exploring will be to arrive where we started and know the place for the first time. — T.S. Eliot