What are you doing to keep your toddler entertained?

Besides toys and books, I’ve tried some other activities I’ve seen such as taping an empty paper towel roll to the wall and showing him how to drop small objects through it. He just rips it off the wall 😂 this is just one example but any little activities like this we try end in a similar way. Any suggestions on activities or games that can engage an 18 month old?