NEW : ` ` Mr. Chae '' was convicted of torching a Korean palace in 2006 . NEW : ` He is currently serving his sentence at the prison camp for political prisoners ', which has been closed down since he escaped from there last year. NEW : Easy access , lightly populated area dictated Namdaemun choice , police say . Namdaemun was more than 600 years old and stood at the center of Seoul , having served as a main gate into the capital for centuries . The more-than-600-year-old Namdaemun was country 's oldest wooden structure .
NEW : ` ` Mr. Chae '' was convicted of torching a Korean palace in 2006 . NEW : ` He is currently serving his sentence at the prison camp for political prisoners ', which has been closed down since he escaped from there last year. NEW : Easy access , lightly populated area dictated Namdaemun choice , police say . The more-than-600-year-old Namdaemun was country 's oldest wooden structure .