BBQ in Kraków

Does anyone know a place in Krakow or nearby where it's legal to use a portable charcoal grill on weekends? I googled it, and the only option I found is Polana Wincentego Wobra near the Zoo, where you need a permit for a bonfire.

However, from what I've read, you don't need one if you're careful, clean up after yourself, and use a portable charcoal grill instead. Can someone confirm this is correct?

Thank You