Nigeria's Osun River, is revered for its cultural and religious significance among the indigenous Yoruba-speaking people.
"What people refer to as water we call it herb, the herb of Osun because it has transcended ordinary water," says Osunyemi Ifarinu Ifabode, the Baba Orisa, or Chief Priest of Osogbo.
"It is not a river without an origin, it has an origin and has become an herb that we use for healing."
The servants of Osun, made up of women, mostly aged 30-60, live in a line of one-room apartments along the side of the Osogbo palace, the royal house of the the Osogbo monarch.
They can often be seen carrying out various tasks on the river from dawn to dusk, from overseeing sacrificial offerings to carrying out cultural activities in the Osun's waters.
Some say the river heals them of afflictions when they drink or bath in the river, and others say it can provide wealth or fertility.
"God has given powers to Osun (river) from the beginning that whomever come to seek the fruit of the womb, that God will grant their prayers, fertility belongs to Osun," says Abimbola Adeyemi a Priestess of Osogbo.
Devotees like Sarafa Afolabi can be seen sitting near the river bank, washing their hands in the water and offering prayers to Osun. "I believe in Osun River," says Afolabi.
But the river is under constant threat from pollution, from waste disposal, and other human activity - specifically the dozens of illegal gold miners whose runoff has filled the sacred river with toxic metals.
Chief Priest Osunyemi Ifarinu Ifabode said "We asked people to stop drinking the herb (water from the river) since it has become contaminated," adding "Also, I have written to the government of Osun State repeatedly to help stop the miners and mining activities which the government promised to take action however, no action has been taken."
The religious leader went on to say "From the look of the river as you can see today the discoloration, the river is contaminated because of mining activities by the miners that is why the river looks like this now, that is the major challenge the river faces today."
Urban Alert, a nonprofit organization that aims to protect the river, conducted a series of tests on the Osun in 2021 and found it to be "heavily contaminated."
The report found lead and mercury levels in the water at the grove that were, respectively, 1,000% and 2,000% above what's permissible under the Nigerian Industrial Standard.
"It seems the government is incapacitated about the problem and thereby exposing residence of the state, in fact people living in more than twenty (20) communities to the effect of the pollution," says Anthony Adejuwon, a team lead for Urban Alert.
"While some people think that the contamination of the Osun River is not resolvable, I am optimistic," says Adejuwon.
"And I believe that it is possible, the government just need to have that political will to save the iconic river."