Richard Colvin Reid , also known as the Shoe Bomber, is a British terrorist who attempted to detonate an explosive device packed into his shoes while on American Airlines Flight 63 from Paris to Miami in 2001. Born to a father who was a career criminal, Reid converted to Islam as a young man in prison after years as a petty criminal. Later he became radicalized and went to Pakistan and Afghanistan, where he trained and became a member of al-Qaeda. On 22 December 2001, he boarded American Airlines Flight 63 between Paris and Miami, wearing shoes packed with explosives, which he unsuccessfully tried to detonate. Passengers subdued him on the plane, which landed at Logan International Airport in Boston, Massachusetts, the closest US airport. He was subsequently arrested and indicted. In 2002, Reid pleaded guilty in U.S. federal court to eight federal criminal counts of terrorism, based on his attempt to destroy a commercial aircraft in flight. He was sentenced to 3 life terms plus 110 years in prison without parole and is currently being held at ADX Florence, a super maximum security prison in the United States.
Question: What prison is Reid being held in?
Answer: ADX Florence