Firefighters called out to a blaze in woodland said it had been started deliberately.
The fire, off Wood Lane, Dinnington, was discovered at 8pm on Tuesday.
That night fire crews were also called out to a wheelie bin set alight on Stacey Crescent, Grimethorpe, Barnsley and another bin on Cemetery Road, Grimethorpe, 10 minutes later.
Police were alerted to the incidents.
Anyone with information should call South Yorkshire Police on 101.