It’s likely some church in your area has an outdoor shrine that could turn into a perfect family outing. (For example, our parish has a beautiful Mary shrine in the back yard and a kind of hidden trail with the Stations of the Cross along the way. And you can find this at Epiphany: A Rosary Garden where each “bead” of the Rosary is a white marble relief of Mary and Jesus and Stations of the Cross Garden featuring 15 large reliefs showing Christ’s passion)
Bring a lunch and your Super Summer Sacrament Scavenger Hunt booklets and spend a little family time in prayer and exploring the grounds for some of the signs and symbols you’ll find there. Free, simple, spontaneous … sounds like it fits in with a nice summer day!