When I'm abroad I always look for beautiful surroundings and nature, forgetting there are sites just as gorgeous right around the corner in my own town.
On sunny days parks in Eindhoven are very much alive and fun! There are many beautiful ones to visit. Like 'Philips van Lenneppark' with a petting zoo, 'Philip de Jonghpark' with great lanes and fun festivities, 'Stadswandelpark' near the center of town with sculptures to look at and Genneper parken, my favorite choice.
Genneper parken has grassy fields and lots of water with the 'Dommel' and the 'Tongelreep' running through. It's really pretty, with great spots to just drop your blanket and chill. Playful dogs, people swimming or playing catch, glasses of wine toasting on fine days. It's such a relaxed atmosphere, someone please play me some Bob Marley!
Tip: Take off your shoes so you can put your open beer bottle in it, no mess guaranteed. :)
Large area on the south of town, navigate to Antoon Coolenlaan 1 - Eindhoven