Reffen is a large street food market featuring cuisine from all over the world. All of the stalls are in colorful shipping containers, which creates a fun, industrial vibe. There are picnic tables all over, bars, a brewery, a small skate park, and petanque courts. It can get pretty busy, so I would avoid peak times if you are coming with kids, but there is plenty of space for them to play and run around. Note that Reffen is not open during the winter months. Check their website or Instagram to see if they're open when you are visiting.