A team of deputy U.S. marshals delivered him early Saturday to the federal Supermax prison in Florence, Colo. The prison is sometimes called the "Alcatraz in the Rockies," CNN reported.
"It is a place of extraordinary security, 23 hours a day in cells, one hour of recreation," CNN senior legal analyst Jeffrey Toobin said at the time of Moussaoui's sentencing earlier this month in U.S. District Court in Alexandria.
Moussaoui pleaded guilty more than a year ago to six counts of terrorism conspiracy connected to the Sept. 11, 2001, attacks, but he was not charged with direct involvement in the plot.
The government sought to impose the death penalty, but a jury sentenced him instead to life in prison without the possibility of parole.