Toys for balcony or VERY small outdoor space?

I'm separating from my husband and our children will go from having a big garden with all outdoor toys I can imagine to living with me in an apartment with a balcony or a small outdoor space that's slightly larger than a balcony. What toys should I bring/get? My boys are 18 months and 3 years old. I'm thinking I'll bring our water table if I get a downstairs apartment, but you can't really do water play if I get a balcony with a neighbour below. Help?