“Before, it was a run-down, abandoned square,” the old priest said, speaking in the local language of Goun. “Today, it’s lovely.”

But its rituals have often been distorted by Hollywood, which tends to stereotype the religion as a source of black magic. In Benin itself, voodoo was battered during French colonisation, when it was demonised by Catholic missionaries.

A dozen years after Benin gained independence, voodoo was banned by Mathieu Kerekou, a Marxist-Leninist who came to power in a military coup.

His elected successor, Nicephore Soglo, lifted the ban, but the religion came under pressure once more with the spread of evangelism in West Africa, whose preachers often compare native religions with sorcery.

According to the latest available official figures, which date from 2013, practitioners of voodoo, who are called vodounsi, account for just 11 per cent of Benin’s population, against nearly 30 per cent Muslim and 25 per cent Christian.

Porto-Novo, a city of about a quarter of a million people, originally developed as a port for slave trade under the Portuguese empire in the 17th century. Its squares – 44, according to Gerard Bassale, head of a local cultural association called Ouadada – are one of its most distinctive features.

Many of them belong to local families, who built their homes there and established temples and housed their divinities as protection. But many of them fell into sad disrepair, becoming a symbol itself of voodoo’s marginalisation. Many blamed squabbles within families about sharing out the cost of renovation.

“They are the identity of our town. They create links between people, they are where important ceremonies take place,” said Bassale, whose organisation is refurbishing the squares. “If they disappeared, part of the town’s history would go with them.”

Restoring each square costs the equivalent of around US$66,000. The funding comes from Cergy-Pontoise, a town in the greater Paris region that has twinning links. Porto-Novo’s authorities are paying for solar-powered lighting for the squares and for cleaning them, but does not maintain the voodoo shrines there, which it considers to be private areas.

King Te Houeyi Migan XIV, the descendant of a long line of local chiefs, is delighted at the rebirth of the squares. French colonisers used a forest that was sacred to his forebears to build Porto-Novo’s cathedral and governor’s palace.

The chief, clad in a magnificent purple gown, pointed to an ancient kapok tree towering over one of three renovated squares near the old palace. “It is a sacred tree. Spirits live there,” said the king. “Every five years, we hold a great party and make sacrifices there.”

Paul Nouatin, treasurer of an association that maintains two of the squares, said there had been an upturn in interest in voodoo – around 20 young people had been initiated into the religion in December alone, he said.

Mito Akplogan Guin, the supreme head of voodoo in Porto-Novo, said he was optimistic.

“Catholics, Protestants, Muslims … all their ancestors (in Benin) were followers of voodoo. Our religion can’t disappear in a flash.”