Alcácer do Sal e Santa Susana - IC 1;EN 120

It's a truck parking lot where, as you'd expect, trucks are usually parked overnight. If you don't disturb anyone, you won't have any problems. It's huge and easily accessible. I repeat, easily accessible, because some people say "easily accessible" when it's a road so narrow you need a monster truck to get in. It's perfect for spending the night; nobody has bothered me, and it's usually quiet.