Population Cap Increasing Buildings

In this post, we discuss the buildings that increase your population cap the most.  As of now, the #1 way to increase your population cap is by filling your 1x1 squares with Tic-Tac-Toe Parks.  They each increase your pop cap by 17,200 and cost 560,000.  So yea, they are expensive.  But when you are higher level, space is worth more than coins.