I have a 17mth old boy and am thinking of taking him to more activities. The paid ones are all good and well but when you attend 3-4 times a week, the monthly tuition fees become a little ridiculous. I have my son attend a playgroup every Sat, Kindermusik once a week and I also take him to the Toy Library at Central library, which is free. It's great and after that, he can run around the kid's library until he gets tired. You can book as many sessions there as you like (each session is 45mins) and they sanitise the toys after every session. We're also starting a playdate sessoin with one of the neighbours next week so I hope he'll like that.
I admit, this is a very demanding age and keeping them occupied actively can be challenging.
