When you're fed up on the park take a trip to the pet shop.
It's free and you get to see loads of fish, guinea pigs, rabbits, hamsters, meal worm, crickets...
and when they are bored or that they can play with the dog toys
Or, sounds a little crazy but go to a train station and just sit and watch people/trains for a bit. or look up where has roads works then park nearby and walk up to the road works to look at diggers, rollers, men in hard hats etc. DS is obsessed with diggers and had a GREAT time just walking up our road when it was being re-surfaced for 6 weeks. He would pull to stop at a barrier and just look at the men and machines. A couple of times I took his snack out with us to make a trip of it even though we were only minutes from home!
These sorts of trips (airports, bus depot, supermarket when you don't need to buy stuff, markets, car or bike shop etc) offer great sensory experience with a range of new sights, sounds and smells.
We also do an easy trip to the local shop (walking distance) when I don't need anything or only a couple of items. DS carries his little shopping basket there and back and chooses a piece of fruit to buy (put in basket, transfer to checkout then back in basket) and I let him put my times into my basket too. We stop outside the shop for a leg rest and to eat his fruit before heading home. Only works if he's able to walk there though and helps to begin teaching what is acceptable behaviour in shops.
