Hi and welcome to the forum.
Your kids are just the age that mine where when we started to take them walking and, though it has taken the younger one sometime to come round to liking it, 9 years later they are going on a 50km challenge walk together in a month.
Mine have always enjoyed it more if there is a proper hill with a pointy top that they can conquer and I never under-sold the difficulty finding 'it is miles and really steep, can you do it?' motivated them more than 'nearly there'.
Ridge
