This used to be the location of the Bangkok Remand Prison, an old and overcrowded prison. Most of it has been torn down and turned into a public park, but three blocks, a cellblock, a side of the prison wall and two watchtowers were preserved and turned into a museum. This museum displays some of the most sadistic punishments imaginable, and these were actually carried out to offenders not that long ago. The museum can only be visited after making an appointment, but some punishment instruments can be seen from the public park outside, so you don’t necessarily need to enter the museum.