Portland, Ore., is No. 1 on the list of metropolitan areas with the most religiously unaffiliated residents (42%), according to the nonpartisan and nonprofit Public Religion Research Institute’s American Values Atlas, a survey of 50,000 people. Seattle and San Francisco were tied at second place (with 33%) on the list, and Denver (32%) and Phoenix (26%) were third and fourth.

On the other end of the spectrum, Nashville was the metropolitan area with the fewest people without any religious affiliation (15%), followed by Charlotte, N.C. (17%), and Atlanta, Dallas, Orlando and Pittsburgh (all with 18%). Some caveats: While many people who don’t believe in God may not attend religious services, there are (of course) faith traditions such as Unitarian Universalism that welcome and include humanists and atheists; many people who might not believe in God may just as likely go to church for spiritual reasons too, or merely because they like it.

Why the regional differences? “Portland is quirky and different, and very attractive to people who may not feel comfortable in other social environments, particularly with a stigma against those who are atheists,” says Daniel Cox, research director at the Public Religion Research Institute.