Toddler ages: 24 months, 24 months, 3.5 years
Materials you'll need:
Who would have thought that this would be such a fun activity invented by the twins. I think having the windows and walls as a support for the blocks helped and that basking in the sunlight sans sleepers felt great. The twins were at this for quite some time...
...and continued the fun even after I put clean sleepers on then in preparation for nap time...