The happiest place on earth is not, as Mickey Mouse and friends would have you believe, Walt Disney World. It’s Mexicali Rose. For here, in one of the East Bay’s oldest Mexican restaurants, located right across from the Oakland City Jail, ex-inmates can relish their first joyful moments of freedom by stuffing greasy enchiladas in their faces. So what if the food is average and Americanized? It’s also abundant and unassuming, decent enough, good with a margarita, and it sure beats eating spread (the notorious lockup snack involving ramen, hot water, Cheetos, and other commissary goodies mixed up in a trash bag). The menu is in English on one side and español on the other, and the jukebox cranks out R&B and soul until 3 a.m. So worry not: Even if you get let out of the slammer in the wee hours of the morning, you’ve still got a place to get fresh with some fresh, fatty food. As one patron said, “There’s no wrongdoing in there, because people just got through doing wrong.”