Mugosi Maningo and Anastasia Juma's homestead lies among a cluster of hamlets that make up the remote village of Nyamongo in far northern Tanzania.

"My wife and I do everything together," says Juma, 27, a petite woman wearing a fuchsia T-shirt and short braids in her hair.

"We're just like any married couple."Almost, but not exactly.

As members of the Kurya tribe, a cattle-herding community with a population of roughly 700,000 spread across northern Tanzania, Juma and her wife, Mugosi, 49, are married under a local tradition called ("house of women").

The practice allows women to marry each other to preserve their livelihoods in the absence of husbands.

Among the tribe—one of more than 120 in the country of 55 million people—female couples make up 10 to 15 percent of households, according to Kurya elders.

The unions involve women living, cooking, working, and raising children together, even sharing a bed, but they don't have sex.

is an alternative family structure that has existed for many years.

"Nobody knows when it started," she says, "but its main purpose is to enable widows to keep their property." By Kurya tribal law, only men can inherit property, but under , if a woman without sons is widowed or her husband leaves her, she is allowed to marry a younger woman who can take a male lover and give birth to heirs on her behalf.

The custom is very different from same-sex marriages in the West, Dinna adds, because homosexuality is strictly forbidden.

"Most Kurya people don't even know gay sex exists in other parts of the world," she says.

"Especially between women."Outdated attitudes aside, Dinna, 29, says is undergoing something of a modern revival.