Let them be completely in charge of the tent, setting it up, keeping it clean, taking it down, packing it away. If they have a buddy along, they can even have their own smaller tent. Be prepared, though, for a sleeping buddy come midnight. Choose a hotel with an indoor pool if the weather is too cool for swimming. If sports are popular and you live in an area where it is possible, attend an event together.
Cultural events are popular, too.
Make certain your grandchild will be interested in, say the opera, before you go there, however. Interactive science museums are normally still a hit at this age. Crafts still have an interest, too. It is a good age to teach a child to sew, knit, or crochet if they seem interested and do not know how. Try to bring some school lessons to life by visiting a working farm, a historical place, a museum.