What interesting traditions.
I once read that in a small town called ålesund every year on June 24, fires are also burning.
Thus, the locals celebrate two holidays at once - Midsummer day (pagan holiday of the summer Solstice) and Christmas of John the Baptist.

I think that the Tradition of kindling fires on the summer solstice
has existed among Norwegians since ancient pagan times.

With the advent of Christianity in your country began to burn such fires.

Thank you for interesting photos, dear @Siggjo