Holding the Nazi war criminal Rudolf Hess as the lone prisoner in Germany's Spandau Prison in 1985 cost an estimated $1.5 million in today's dollars. Then there is Guantnamo Bay, where the expense now works out to about $13 million for each of the 40 prisoners being held there. According to a tally by The New York Times, the total cost last year of holding the prisoners ... paying for the troops who guard them, running the war court and doing related construction, exceeded $540 million. The $13 million per prisoner cost almost certainly makes Guantnamo the world's most expensive detention program. The military assigns around 1,800 troops to the detention center, or 45 for each prisoner. Judges, lawyers, journalists and support workers are flown in and out on weekly shuttles. The estimated annual cost of $540 million ... does not include expenses that have remained classified, presumably including a continued C.I.A. presence. But the figures show that running the range of facilities built up over the years has grown increasingly expensive even as the number of prisoners has declined. A Defense Department report in 2013 calculated the annual cost of operating Guantnamo Bay's prison and court system at $454.1 million, or nearly $90 million less than last year. At the time, there were 166 prisoners at Guantnamo, making the per-prisoner cost $2.7 million. The 2013 report put the total cost of building and operating the prison since 2002 at $5.2 billion through 2014, a figure that now appears to have risen to past $7 billion.