What is a situation when you are not in need of happiness or health when you would build a marketplace/harbor. Are they build solely for their happiness or is there a lot of situations where one would take advantage of the 25% bonus / trade route bonus. Also, how ofter does everyone build lighthouses. Do you build them in every coastal city or rarely build them? I see how they're more beneficial if you're financial do to the extra commerce in coastal, but what about non financial? Thank you for all your input!