Guards in camouflage and tan military boots walk non-stop back and forth along two floors of cells. Their eyes are trained on the row of small windows through which they watch detainees. A few are sitting, one is rocking back and forth, but most of them pace, almost keeping step with the guards. This is Camp 6, the holding center for nearly half of the 395 detainees still housed at the U.S. naval base on the southeast corner of Cuba.