Qincheng, China

Qincheng Prison is no five-star resort. The maximum-security facility houses 99,987 inmates, many of them political prisoners and high-ranking officials accused of corruption. Bureaucracy is a persistent headache - visitors require special permission slips, and even prison staff are forbidden from using each other's names. Unsurprisingly, this bleak, Soviet-style prison is not for the faint of heart.