I have visited Ciudad Juárez just for few hours. You can visit for one day without visa from american's city El Paso. During entry to Mexico I have not any big luggage so I was not checked. So maybe in this way you can stay longer. I have just visited border's city Ciudad Juárez. At first sight is bright differencing between both countries. You can see a lot of foot clearers on the streets. I have never seen so many optics and chemist's on one place like here. As soon as you sit down at restaurant, children and women are offering you everything to sell. I with my friends tested Burritos.
Not only in the USA you have to drink alcohol at paperback on street.