St Agnes Abbey
From Tardis Wiki, the free Doctor Who reference
St. Agnes Abbey was home to a sisterhood of nuns under the control of one of the Gorgons, who inhabited the body of the Abbess. It contained a garden of stone statues which had formerly been humans transformed by the Gorgon, secret passageways constructed during the Protestant Reformation, and a portal leading to the Gorgon Homeworld. Sarah Jane Smith defeated the Gorgon and freed the nuns from her influence. (SJA: Eye of the Gorgon)