If you live in a town large enough for bus service, you may want to look into riding the bus around as an inexpensive form of entertainment. We took The Boy on our local town bus route and had a grand old time. We were the only ones on the bus for the entire trip. He is young enough still to be a free ride and the adult fare was less than $2.
We have a country bus service that we plan to try one of these days. That will be a much longer ride, but will still cost less than $2. Plan ahead and bring a diaper bag with a diaper change if needed, water and snacks. Check the schedule online, then confirm your route with the driver when you get on the bus.