Fighting has raged along ethnic lines, between forces loyal to the mainly ethnic Dinka government and the opposition fighters, most of whom are ethnic Nuer.
But while the rest of the country is divided, Ganyiel, sheltered by marshes, which form natural defences in the centre of the country, has grown as an ethnically mixed town that could serve as a model for nurturing pockets of peace elsewhere.
"We're a peaceful island within South Sudan," said Ganyiel's town director, Michael Lot.
"Just two months ago, 2 700 Dinka arrived here, fleeing food insecurity and conflict. They are welcome. The war is political. It's not between us people."
A third of South Sudan's 12 million population has fled their homes amid persistent reports of gang rape and ethnic violence.
Despite its well defended location, war remains a constant threat in Ganyiel and it is regularly hit by floods that destroy the harvest.
The town has depended on food distributions by the U.N.'s World Food Programme as long as residents can remember.
But in contrast to other areas, marriage and trade among different ethnic groups is common while five aid agencies have coordinated to provide basic education and healthcare.
Each evening, as the sun sets, the town's red dirt airstrip fills with people taking walks or playing football in the evening breeze.
The bucolic peace is sometimes frayed by disputes over cattle, land and water, which can escalate into feuds between clans.
And with a prevalence of guns even among civilians, killings and revenge killings are not uncommon, said a South Sudanese aid worker who asked not to be named.
Mary Deng arrived in Ganyiel two months ago. She's a Dinka and her journey north took her several days.
"Our community was accused of intermarrying with Nuer people and we no longer felt safe," said the mother of three.
"We move freely in Ganyiel and interact with the community," she said, sitting on the ground outside her hut, holding her youngest son on her lap. "Intermarriage has been common in this area for a long time."
This is largely due to cattle trading, facilitated by the town's trade union that promotes livestock sales in the surrounding region and as far north as the Sudan border.
"Proximity to the River Nile has linked Ganyiel to Juba and the outer world, thus making it a hub for the entire region. Fish and livestock products are exported through the port to the capital and other markets," said Raphael Ndiku, a Ganyiel-based aid worker with German agency Welthungerhilfe.
Commodities and people have always moved in and out of the town, mixing its residents with outsiders.
"Trade was flourishing here before the war," said Kharbin Banybor, head of the Panyijiar County Trade Union.
"The trade and free movement led to a lot of intermarriages, even with Arabs from the north," he told the Thomson Reuters Foundation.
Adut Amal, a Dinka woman from the town of Yirol, about 60 km (40 miles) to the south, is the widow of a Nuer man. Sitting on a mattress in the shade, she is wrapped in a floral robe.
She has lost her eyesight and doesn't know her age, but still remembers the day she came to Ganyiel after her marriage.
"My husband was a trader who knew my family well. It was difficult to leave my home and move away, but the community welcomed me openly," she said, recalling her difficulties learning the Nuer language and the culture's songs and customs.
"I still sing Dinka songs, but I know that Ganyiel is my home," Amal said. "The country is in crisis, but to me all people are the same."
Access to food has been a struggle in Ganyiel and the townspeople depend on food drops by plane.
The sparse selection of goods in the market are brought in from Juba by Nuer traders and are shipped up the Nile through government-held areas by their Dinka partners.
"It's increasingly difficult and the markets are almost empty now, but we try to keep our businesses going," said shopkeeper Kuany Thiong, standing by his stall selling flour, onions and yeast. There are few vegetables in the market – families live mainly on sorghum and beans.
Helicopters and small airplanes arrive on the dirt airstrip several times a week, bringing in aid workers and health personnel.
"They have figured out how to make it work, covering the town's basic needs," said Ian Ridley, head of South Sudan’s United Nations Office for the Coordination of Humanitarian Affairs (OCHA).
"The need is still great, even though Ganyiel enjoys relative peace and safety due to its geographic location."
For Banybor, the trade union head, Ganyiel is a model town, even with widespread poverty and hunger. "Both the humanitarian response and the interethnic relations work. A lot can be learned from it," he told the Thomson Reuters Foundation.
So-called bottom-up grassroots peace initiatives need to be pursued as well as peace talks at the top level, said a Juba-based expert on conflict monitoring.
The December-to-May dry season usually intensifies clashes and there is little chance of peace talks to end the war, diplomats and analysts said last month.
"The war is all around us and it's dangerous," said Banybor. "I'm happy that we get to feel safe in Ganyiel for now."