Well, an English guide is important when you traveling in Xi'an because this city is full of historical interests. If you would like to have an efficient tour in the downtown area, please take taxis to your destinations. The taxi fare of Xi'an is very cheap in my mind. Of course, if you go to Terra-cotta warriors and horses, those ones in the suburb, you may have to bargain the price with the drivers. Maybe 100yuan to 200yuan~