There are few things about Dungeons and Dragons that I enjoy more than imagining up towns and cities. What sorts of businesses are there? Is there industry? Can I buy clothing made from yams? Just how big of a turnip can a fellow buy for thirty-seven pounds of gold coins? Placing inns, taverns, houses of ill repute, and merchants is a delightful way to pass the time on a lazy day. The only thing more fun is to open up a landscape for players to develop themselves. In the best of games there might not even be a chance to do this beyond the players deciding to build a castle and then NPCs populate the area around it with whatever it is that they do. But the current game has an entire nation (albeit a rather tiny one) that needs to be rebuilt, practically from nothing, and it will fall to the players to do most of the planning.
There are of course some notable exceptions. One of the NPCs that has latched on to the group will want to build a spectacular inn with what they hope will become a regionally renowned pub and restaurant. Another NPC is going to want to build a chapel. Others might seek to build modest industrial and commercial endeavors such as a carpentry shop, a blacksmith, and a livery stable. They have the ruins of a once great city to use as a template and can scavenge building materials from the hundreds of structures that were knocked down when a semi-crazed dark elven archmage sneezed out a rumbling curse of an earthquake that leveled everything. The only thing that needs to be brought in to accomplish these goals is labor because the humans had all disappeared and everyone else had either been killed or sold into slavery to the orcs to the north.
This is the blank canvas upon which a masterpiece will be rendered. I already have a name for one of the taverns and it is a terribly clever bit of wordplay that will undoubtedly go completely unnoticed. The families that are poised to settle into the rejuvenated nation are already established. Trade will grow once they are settled in place. Things will begin to happen as soon as the plant and wildlife begin to be reestablished in the ruined landscape torn asunder by the foul magicks and insidious rites of the night hags that had been running amok for far too long. It will be a lot of work and the players will by necessity have to devote a good deal of time to hammering this all down. But then nothing worth having is easy.
Unless you are looking for a good tapestry.