Well, building a city (I saw that in your first post but decided to ignore it thinking I was misunderstanding) is an enormous undertaking. For a city your talking about thousands of residents, enough nearby cultivation to provide food for all those folks/ or enough trade to suppliment what cannot be grown/raised locally. All those people need work that will supply them with the money they need to buy, at the very least, the necessities for daily existence. That money has to come from somewhere, usually trade with towns/cities nearby. Now in a fantasy game like Pathfinder money usually flows pretty freely from monsters to PCs, but I seriously doubt a single adventuring group is going to supply enough coin to keep an economy the size of a city running all on their own. Nevermind the need for raw components to build a city (quarried stone, lumber, iron) and all the raw components needed to keep a city running (fabrics, more metals, oil, etc etc).
If you do manage to build a city, just the fact there is a city fairly close to another city means people are going to know about it. Even if you built the entire thing with magic instead of craftsmen, the wizards/druids/ etc that built it are going to be talking. The people you will need to get to create farms nearby will talk. The merchants you will need to have will set up trade routes which will get the word out.
I do have a very important question though. Did you get the permission of the local king/nobility to build your city? Most societies around which most fantasy worlds are built are based on the feudal system, in which case all the land in the kingdom actually belongs to the king. The king then gives nobles permission to manage sections of the kingdom (the nobles usually pay money upfront for this) for which privilege they pay the king taxes. Even the uncleared lands are owned by the king. It was often illegal for peasants to hunt woodlands without special permission of the local lord.
