Camping in churches—or "champing"—is an increasingly popular activity in southeastern England. Possibly because adherents don't call it "churmping."
The growing trend dates to 2014, when the Churches Conservation Trust opened the medieval All Saints' Church in Aldwincle, Northamptonshire, to overnight guests willing to pay a relatively small fee (it's currently £55/US$68 per night).
The following year, the organization expanded champing to four churches, and three more were added in 2016. This year you can choose from 12 historic houses of worship spread all across England. Champing season starts in May.
The appeal for visitors has to do with sleeping in a truly unique, historic space—which you'll have all to yourself overnight (sounds pretty spooky, now that we think of it). You'll also be close to quaint English villages and plenty of natural beauty. And you'll be helping to pay for the upkeep of centuries-old churches (you do not have to be religious to participate).
Keep in mind, however, that the experience is closer to camping than staying at a hotel—in other words, the buildings are unheated and don't have running water. Still, local volunteers set the churches up before guests' arrival with snacks, electic candles, sleeping bags, and pillows. So if you're traveling from another country, you don't have to lug those bulky items onto the plane.
For more information or to book a champing stay, visit the Churches Conversation Trust website.