The idea for a prison school was thought up by former director of prisons Chua Chin Kiat in 1999, and became a reality a year later when the Kaki Bukit Centre (Prison School) opened.
It was relocated to Tanah Merah Prison in 2011.
The four-storey Tanah Merah Prison School building houses, among other facilities, several classrooms, a science lab, an IT lab and even a well-stocked and planned library.
The classrooms are simple and filled with spartan furniture such as tables and chairs, but also boast equipment like projectors.
In the science lab, stools are bolted to the ground so they cannot be thrown, while items such as scissors are locked away when not in use.
The library, situated on the ground floor, could easily be mistaken for a mainstream school library.
It carries a wide selection of encyclopaedias, books - including those on topics such as social science, religion and philosophy - and magazine titles like the National Geographic and Reader's Digest.
The library is also stocked with relatively new reads, like former United States Secretary of State Henry Kissinger's 2014 book World Order, and literary classics such as Great Expectations by Charles Dickens. Inmates are able to borrow these books and take them back to their prison cells to read.
At a section near the entrance of the library, the prospectuses of various tertiary institutions, including the polytechnics and universities, are available for students to browse and plan their higher education.