The small prison was built in 1856 and is still active to this day. With only two small holding rooms, one cell measuring 1.8 meters by 1.8 meters. Another room is larger, measuring 1.8 meters by 2.4 meters. These two rooms are only separated by a narrow corridor. With its number and size, this prison holds the Guinness World Record for the 'smallest prison in the world'.

According to the Sark Estate website, the Guernsey Court ordered the construction of a new prison in 1832, as the old prison was considered unfit. However, budget constraints delayed the start of building the new detention facility for over two decades. This prison was finally completed in 1856 and has been in operation since then.

Although this prison has only changed slightly in terms of structure, its facilities have been equipped with electricity and heating. However, this prison still does not have windows. The most famous prisoner in Sark Prison is Andres Gardes, a French nuclear physicist who is unemployed and believes that he is the rightful heir and owner of Sark Island.

Because no one responded to his claim seriously, he decided to attack the island as a one-man army. He posted posters announcing his invasion on the island. He was arrested and his invasion was thwarted.