U.S. military guards move a detainee inside the detention center in September 2010. At its peak, the detainee population exceeded 750 men at Guantanamo.
Muslim detainees kneel during early morning prayers in October 2009. Cells are marked with an arrow pointing in the direction of Mecca, regarded as Islam's holy city.
A soldier stands near a placard on the fence line of the detention facility in January 2012.
A Quran sits among a display of items isssued to detainees in September 2010. The suspects are given a prayer mat and a copy of the Muslim holy book as well as a toothbrush, soap, shampoo and clothing.
A U.S. military guard walks out of the maximum security section of the detention center in September 2010.
A German shepherd police dog undergoes training exercises in October 2009 at Guantanamo Bay.
A camp librarian views artwork painted by detainees in September 2010.
A detainee rubs his face while attending a "life skills" class inside the Camp 6 high-security detention facility in April 2009.
A seat and shackle await a detainee in the DVD room of the maximum security Camp 5 detention center in March 2010.
U.S. Marines join in martial arts training at the U.S. naval base in September 2010.
Members of the military walk the hallway of Cell Block C in the Camp 5 detention facility in January 2012.
Guards move a detainee from his cell in Cell Block A of the Camp 6 detention facility in January 2012.
A detainee waits for lunch in September 2010. The cost of building Guantanamo's high-security detention facilities was reportedly about $54 million.
Marines get an early-morning workout at the U.S. naval base at Guantanamo Bay in October 2009.
A bus carries military guards from their night shift at the detention center in September 2010.
A military guard puts on gloves before moving a detainee within the detention center in September 2010.
Members of the U.S. Navy move down the hallway of Cell Block C in the Camp 5 detention facility in January 2012.
A U.S. military guard holds shackles before preparing to move a detainee in September 2010.
An American flag flies over Camp 6 at Guantanamo in June 2013.