A conserved screen in the small Vale of Glamorgan church of St Cadoc’s, Llancarfan, will be unveiled next week.
The gilded early 15th Century reredos is described as extraordinarily intricate.
The Church in Wales says it's been painstakingly returned to former glory by a team of three specialists, over the last six months.
It says the mystery remains as to why a work of the magnificence of the reredos is tucked away in a village church like St Cadoc’s.
One theory is that it began life elsewhere and only moved to Llancarfan when it was 200 years-old, in the mid 1600s.
The end of four years of conservation work at the church, which included the discovery and restoration of Medieval wall paintings of St George and the Dragon and the Seven Deadly Sins, will be marked with a Celebration Evening.