The Metropolitan Detention Center, Guaynabo is a United States federal prison facility in Guaynabo, Puerto Rico which holds male and female inmates of all security levels who are awaiting trial or sentencing. It is operated by the Federal Bureau of Prisons, a division of the United States Department of Justice. MDC Guaynabo is located next to Fort Buchanan U.S. Army base, and is 6 miles west of San Juan, the capital of Puerto Rico.