- relatively empty on a Saturday or Sunday.
- not near houses (because of the pests it'll attract).
- publicly owned (or privately, and easy to get permission), but not a park.
I'm willing to "rent" the land from a homeowner or business, or have a quick and dirty fight on an unused piece of public land. Renting shelters in parks is out of the question because of the mess it'll leave behind. I don't think this is against the law (is it littering if it's biodegradable after a heavy rain?*) but I don't want to trespass, either.
*ETA: OK, YES IT'S LITTERING. New plan: We'll put down drop cloths and take it all with us when we leave.