Here I present a list about places, you can spend a night for free when you travel. Of course it matters where you need that place, since noone would spend the night outside in Lapland, but in a warmer country it could be a solution too. Therefore now I just publish a raw list of places (and I'm waiting for more ideas in comment, I'm updating the post continously). If any time in the future you have no accomodation nor money in a foreign town, just open this list, and survive the night!