The twinning ceremony was held as 18 new statues were inaugurated on the site at Carnöet in Côtes d’Armor and will be marked next year when Easter Island sculptors visit to create one of their giant moai sculptures.
Their new statue will be five to six metres high, said Philippe Abjean, who founded the Vallée des Saints in 2009.
It will join 134 others on the Quénéquillec hillside site that overlooks the Forêt de Fréau.
Last year, more than 480,000 people visited to see the statues that are paid for individually by groups or families.
The long-term aim is to have statues of all of Brittany’s 1,000 saints – with about 20 being ordered each year and sponsors funding the work.
Mr Abjean said the idea had been “to create an open-air cathedral that would have a spiritual dimension and also pass on artistic know-how”.
“For Connexion readers, we also want to remind them of our close links with Britain, and especially Cornwall and Wales and the Celtic heritage.”
One of the 18 statues revealed was of Saint-Dewi, or Saint David the Welsh patron saint, a 3.5m work by Welsh sculptor Paul Kincaid.
The €15,000 total cost was paid by 4,350 individual and company sponsors. Using granite from a Welsh quarry, it was shipped from Cornwall to Brittany.
It had been hoped to do the same with the moai statue but the Chilean ambassador – Easter Island is Chilean – said plans to carve the moai on the island and ship it to Brittany failed as local law bans stone leaving the island.