Developer Zynga has announced the addition of a city simulator to the 'Ville brand of Facebook games.

Billed as "Monopoly meets Main Street", CityVille is a social networking game that gives players the tools to build a virtual city, balancing goods and services to meet the needs of the residents.

In typical 'Ville fashion, players will be able to visit their friends' cities and help speed up their growth by cutting construction times and trading collectible items. There's even an option to open businesses in your neighbours' commercial zones, establishing a franchise which improves your own city.

Another feature of CityVille will be rare buildings that are unlocked by completing a series of tasks. Zynga hasn't revealed much information on this mechanic, but we're assuming it will involve goals such as achieving a certain population or income level.

According to the CityVille website, Zynga is putting the "finishing touches" on the game at the moment. A beta version is expected at some point in the very near future.