My P5 son has been quite good in his spatial reasoning. He can picture a shape or object in 3D easily. Aside from Minecraft (yes, the game), I attribute this to him playing a lot of puzzles, blocks and board games when he was younger.

According to the Association for Psychological Science, how often children played with certain toys ties in with their spatial reasoning skills. Children who played with puzzles, blocks, and board games often (more than 6 times per week) had higher block design scores than did children who played with them sometimes (3 to 5 times per week), or rarely.

Among the many educational block tools in the market, I personally used and like the Nikitin Material range from Lern Spiel Verlag. They are recommended for children from 4 years and above.

My son used to play with the Geocubes set, which I still have. It was responsible with helping my son to be more aware of the 3D space and recognise colour and shapes at the root of perception. It also trained him, in a smaller way, to focus on the task at hand too, although I think he has lost this already. 

If you think these are only meant for the kids, you are so wrong. Some of the tasks can be quite challenging for adults like me too! 

The #11 Top Learning Resource of 2015 is the Nikitin Material Geocubes.