From an AP news report:
In northern Bucharest, in a busy residential neighborhood minutes from the heart of the capital city, is a secret the Romanian government has long tried to protect.
For years, the CIA used a government building — codenamed "Bright Light" — as a makeshift prison for its most valuable detainees. There it held al-Qaida operatives Khalid Sheikh Mohammed, the mastermind of 9/11, and others in a basement prison before they were ultimately transferred to Guantanamo Bay, Cuba, in 2006, according to former U.S. intelligence officials familiar with the location and inner workings of the prison.