Once, I was invited to attend the youth group that my aunt and uncle ran for their church. We made viking boats from cardboard and then painted and varnished them.
The next week, we took the boats to the outdoor Steprock swimming pool. At the base of the masts, we stuffed balls of cottonwool soaked in meths and set light to them. It was a magical sight as they drifted away, beneath the flood-lit walls of the ancient, ruined castle.
Thirty years later, this activity was the inspiration for the equally magical 'viking-style' funeral of our beautiful, but profoundly handicapped, 3 year old daughter, Hermione Rose. See here.