The frugal traveler looks at a hotel and sees extortion. Even a hostel is unnecessary, and a campground isn’t much of an improvement. Twenty dollars a night to sleep on the ground? The frugal traveler knows better.
He turns to stealth camping. Any place can be a campsite, if you lower your standards enough. Enter the rest stop, the semi-flat mountaintop, the park bench in the middle of a city. It might be inconvenient, and it might be illegal, but the frugal traveler knows a free night is worth it.
Stealth camping comes in three flavors.