there are several bus lines that run all around the are if you are willing to pay the prices. you really dont need a tour of the city, its easy to navigate and most people will help you if you are lost. honestly its hard to get lost though. the streets are labeled in numerical order and the avenues are fairly easy as well. there is really nothing to tour in the area either. i would say go to ground zero for sure, and the stock exchange which is right by it. dont go to any of the window displays, they are giant let downs and are really not impressive. and eat lots of food!