Holywell town centre is taken over during the Cadi Ha festival
Every May Day the town centres of Holywell and nearby Caerwys are taken over by a procession of dancers led by Cadi, a man in women's clothing!
This year, a band of musicians and 12 Flintshire primary schools are taking part in the Cadi Ha festival when children, their faces coloured black, dance through the streets in a tradition going back 200 years.
It was started by mining communities of west Flintshire and, traditionally, it was men who danced with coal dust to mask their faces black.
Chris Bailey, the chair of the organising committee, explains: "One theory is that the churches didn't approve of the dancing so the men coloured their faces so they couldn't be recognised. Today the children use theatrical paint.
"Two characters lead the procession: Cadi, a man wearing women's clothes, and Bili, who wears black clothes. There is also a man carrying the 'cangen ha', a tree branch decorated with ribbons."
In the early 20th Century Lady Herbert Lewis of Caerwys, one of the pioneers of folk-song collecting in Wales, recorded residents of Holywell singing the traditional song that accompanies the procession.
As Chris explains, the words of this song differ according to which village you're from.
The tradition lost ground after World War I but interest was revived in the 1970s and '80s when a local singer, Ieuan ap Siôn, gathered a group to sing together every May.
When Chris began organising the event in 1998 five schools were involved but this year 12 are expected to take part, as well as dancers from all over Wales including one group from closer to home, Dawnswyr Delyn, Mold.
Chris is keen for young people to continue the tradition.
"I'd rather see Flintshire's children taking part in Cadi Ha than trick or treating. Their grandparents would have known all about it," he said.
Menter Iaith Sir y Fflint, the Flintshire Welsh Language Initiative, includes the Cadi Ha festival as part of their Flintshire Welsh on Tour Week.
Rebecca Davies, language and heritage officer for the group said: "Since its revival in 1998 the festival has gone from strength to strength, and we are sure that the locals will turn out again this year to support the dancers and join in the fun."
The festival (1 May) begins at 10am when participating children will follow the band up and down Holywell's High Street. It continues in the afternoon in Caerwys Square.