Theoretically anywhere, but
not in Abisko National Park - where you hike the last 15 km of Fjällräven Classic Sweden. There are regulations within the national park regarding where to camp or light a fire. These regulations must be observed. Within the national park you’re only allowed to camp or light a fire at a special tent location near Nissanjåkk, 5km from Abisko Tourist Station. You can also camp at Abiskojaure Cabin, in the National Park, the space is very limited there so you have to have a campign ticket that is being picked up at checkpoint Keiron. We recommend you to camp around or before checkpoint Kieron.
You can find out more about the right of common access, which allows free camping under certain conditions,
here.