Every week for the country thing? Once a month, fine. But every week?? Ain't nobody got time for that!
We have:
If at the seaside:
(In winter) we eat our chips on the seawall, watching the waves.
Look for a stone with a hole in it.
Get a treat from baker's to eat on the way home.
Build a sandcastle that DH will throw rocks at. When DS was younger he'd have great fun collecting sandcastle stones 
Easter: I hide a little bunny rabbit keyring somewhere unusual. When it's found the "winner" gets a little chocolate. Has been in the fridge, in the loo roll tube, on top of a wardrobe, behind the TV, taped to bottom of a kitchen chair. The chocolate prize is guarded in a little closing bunny rabbit egg cup holder thing, that DS won when he was about 4, which sits in top of the microwave. Sometimes it has taken a fair few days to be found 
When we visit DHs parents, we stop at Super Sausage, and have brunch, DS used to love the motorbikes.
Christmas: read/listen to a book and eat the special tree chocolate in an unusual place. DS has sat in the bath, under the kitchen table, in the car, laid under his bed, in the cat basket, in a wardrobe, on the middle stair, all sorts.
Ongoing. Hide the ladybird between DH and DS. There's a little rubber ladybird that DS had when he was wee. It now gets moved around a lot. So DS will put in DHs coat pocket, he'll find it at some point, he'll hide it in DS's sock drawer, he'll then find it and hide it in DHs car, it then might move to DS swimming bag etc.... They've been doing this for YEARS, sometimes not finding it for weeks and weeks. Somehow, they've never lost the "Muriel". Occasionally I will find it and am always tempted to move it!
If we go to Harvester, we all order for each other.
Errmmmmmm I think that's it?