Probably in context yes, but not actually a new thing. St. Brigid's (formerly just plain old Brigid) eternal fire burned at Kildare for hundreds, if not thousands, of years until Cromwell's men put it out.

The Paschal Fire that St Patrick is said to have lit on Slane Hill was lit against the fire that the Irish lit every year in a rebirth-type ceremony (the thing here being that every fire in Ireland was supposed to be extinguished and then relit from the central fire). These fires were lit at Tara and before that at Uisneach.

So fires at were parts of ancient ceremonies in Ireland at least and there's documentary and physical proof - the fires on the Hill of Allan and the fires at Navan Fort being good examples.

In Antrim, for example, there is great evidence for lighting fires in or on older monuments, but you'll have to read my next book for more info :-)

The huge capstone of Ballyganner wedge tomb was cracked when a fire was lit on top of it to celebrate a local GAA victory!

The Irish like lighting big fires. Obviously, they don't celebrate Guy Fawke's night, so they use any other excuse for a fire. There are always big bonfires at Hallow'en to keep the evil spirits away.