Indoor museums, play-gyms are great and usually have membership options for frequent use. Other than that: puzzles, toys, paint/crayons and an easel, band instrument sets, train tracks… if you want to collaborate: making playdoh is fairly easy, as is making non-stick/non-staining slime. We usually do a mini parade and have our son make a drum out of an old coffee-container, a mallet out of sticks and paper and a headdress out of construction paper, etc.
