It's a walk about the perimeters of Exeter, through lovely parks, university grounds, past rivers and canals with lots of variety for young and old. You will pass plenty of play areas for your children and to have a rest. Pubs and restaurants are never far away. It is a long walk (12 miles) but easily achievable in a full day and if you have enough there are plenty of buses to take you back because although you are mostly walking through nature you are never far away from civilization. I did this walk when my kids were nine and 10 and they still talk about it.
You can start at any edge of the city to pick up the trail and is well sign posted with green circles.
www.exeter.gov.uk/index.aspx?articleid=1502
+44(0)1392 265890
Google map: bit.ly/n3sZ01