Next year, for the first time in a millennium, a pagan temple will welcome Reykjavik’s faithful. The heathen house of worship, vaguely resembling a misshapen meringue, will be aligned with the sun’s path and burrowed into a hill near the city’s airport. There, like the Vikings of old, members of Iceland’s neo-pagan Ásatrú movement will be able to feast on horse meat, swig from goblets of mead, and praise deities such as Thor, the god of thunder, and Freyja, the goddess of love.

At first glance, the scene might appear bizarrely anachronistic. But although Iceland officially adopted Christianity around A.D. 1000, paganism never really disappeared from the Nordic island. The religious traditions of the Norsemen lived on—in mythology and poetry, in popular Icelandic names like Thorstein, in widespread belief in invisible elves and nature spirits. Eygló Svala Arnarsdóttir, an Icelandic journalist and a self-described atheist who has attended Ásatrú ceremonies, told me, “Icelanders have never really been strictly Christian,” noting that when they accepted Christianity, they did so under the condition that they be permitted to quietly practice paganism. “It’s not that people necessarily believe in the old Norse gods or have secret ceremonies in their basement,” she said. Instead, she explained, pagan values are “ingrained into our culture.”

Ásatrú was founded in 1972, but its following has climbed steeply in recent years, doubling since 2009 to nearly 2,700 members. (Iceland’s population is only 329,000.) Explanations for paganism’s resurgence range from disaffection with the state Lutheran Church, to spiritual dislocation in the wake of the 2008 financial crisis, to a harmony between the homespun faith and Icelanders’ liberal values, including support for environmentalism and gay marriage.

Indeed, Ásatrú approved gay ceremonies in 2003, seven years before same-sex marriage became legal in Iceland. The Web site Gay Iceland recently reported that, amid a broader boom in gay Icelandic destination weddings, “more and more travellers are opting to get married here in the Old Norse way.” Ásatrú’s chief priest, Hilmar Örn Hilmarsson, told the Web site that he attributed the “explosion” in pagan same-sex weddings to the fact that “pagan belief is very inclusive.” Wayne Sievers, who traveled from Australia to wed his partner, Paul Gane, beside a fjord last year, agrees. Sievers told me that the Ásatrú priestess who married them said the round of thunder and lightning before their ceremony was a gesture of acceptance from Thor.

As for whether Vikings back in the day were as tolerant as Iceland’s latter-day pagans, Arnarsdóttir hesitated. “I’m not really sure they were.”