(CNN)In a small forested grove in Southwest Nigeria runs a river, and in the river runs Osun, goddess of love and fertility.
On the brink: Inside the project to save Osun Oshogbo
One of a pantheon of Yoruba deities, Osun goes by many names around the world: Ochun in Cuba and Oxum in Brazil, where she is the nations' patron saint. But for the Yoruba people, numbering some 40 million, she is Osun, and dwells in the waters of the Sacred Grove, just outside the city of Osogbo.
Worshipers come to the grove, a UNESCO World Heritage site, at pivotal moments of their lives, to visit her shrine and pay tribute in the form of offerings and prayers.
"When you come here and tell Osun 'I am looking for a baby,' you get a baby; 'I'm looking for a husband,' you get a husband; 'I am looking for money,' you get money," explains priestess Osafunke Iworo Oshun.
"Whatever someone asks, Osun will always give the person because it's important for the society."
But Osun is under threat, and if things continue as they are, one day she may not be able to answer the prayers of her followers at all.
Osun Oshogbo Sacred Grove is one of only two UNESCO World Heritage sites in Nigeria, but despite its status, it faces an uncertain future.
Founded some 400 years ago, it's the largest sacred grove to have survived the spread of Christianity and Islam in Nigeria (in the intervening years, many groves were destroyed, deemed an unacceptable symbol of pagan idolatry). That Osun Oshogbo remains standing is largely due to the efforts of one woman: Susanne Wenger.
If the name doesn't sound Yoruba, that's because it's not. Wenger was an Austrian expatriate who moved to Nigeria in the 1950s. Inspired by Yoruba mythology, shed began mentoring a team of local artists to protect local cultures and beliefs through their artwork.
The legacy of Wenger is all around the Sacred Grove. Alongside Osun, a statute of Iya Mopo, the goddess of women's professions, looms large among the undergrowth. In each arm, she holds a vestige that symbolizes the various traditional industries in the country, from pottery to palm oil.
"The art itself speaks to people in different ways," says Robin Campbell of the Susanne Wenger Trust. "If you speak to art historians who are experts in African Modernism, this is one of the best examples of [it] on the continent."
But like Iya Mopo, who's following has largely died out, the artworks are beginning to diminish. Shrines and sculptures are feeling the effects of nature and time, and restorative efforts are feeling the same. Susanne Wenger died in 2009, and the team who maintain the grove are aging, and their successors are too few.
"Susanne's team of artists... started when they were young but 40 plus years and now they're old... in the last five years, we've lost three artists," explains Campbell.
Adebisi Akangi is one of only two artists alive who can still work in the particular cement design of the original artwork. He has his own business, but works part time to maintain the statues he created as a young man in the 1960s.
"The work is very important and I really enjoy it," he says, but Akangi knows he won't always be around to maintain the grove. Therefore Akangi is passing on his skills to his son, "but without reliable funds for steady work, no one will be able to afford to do [this]."
Campbell says the Trust needs money for the next five years to complete their ongoing restoration work, as well as train a new generation of artists.
"It is the most beautiful natural spot in whole of Yorubaland, if not the country -- and I think the most impressive sculpture garden in the world," Campbell argues. "We have to keep it and if we don't restore it now, we risk losing it forever."
And forever is too short a time for the gods.