Pack some snacks and enjoy a fun family day out at Haldon Forest Park. There's loads of space for the kids to run about and get some exercise.
You'll have sightseeing choices galore when spending time in Exeter. Haldon Forest Park is an ideal place to begin here, but there are lots of other worthy sights to explore. University of Exeter, Exeter Cathedral, and Powderham Castle are close to the outdoor recreational space and will fill in your day nicely.