It's Xinqiao prison in Lanzhou, Gansu.
Prison is the penalty execution organ of the state. Prison, as the penalty executing organ of the country, plays the function endowed by law by depriving or restricting the personal freedom of criminals. Prisons provide scientific, civilized and effective education and management to criminals, correct their bad habits, guide criminals to develop working habits, master basic professional skills, transform criminals into law-abiding citizens, and prepare for a smooth return to society.