"The Mousetrap" is the longest continuously running play ever. In which theatre did it premier?

As a stage play, Agatha Christie's "The Mousetrap" had its world premier at the Theatre Royal, Nottingham on 6 October 1952. It was originally directed by Peter Cotes, elder brother of John and Roy Boulting, the film directors. Its pre-West End tour then took it to the New Theatre Oxford, the Manchester Opera House, the Royal Court Theatre, Liverpool, the Theatre Royal, Newcastle, the Grand Theatre, Leeds and the Alexandra Theatre in Birmingham before it began its run in London on 25 November 1952 at the Ambassadors Theatre. It ran at this theatre until Saturday, 23 March 1974 when it immediately transferred to the larger St Martin's Theatre, next door, where it reopened on Monday, 25 March thus keeping its "initial run" status. The London run has now exceeded 25,000 performances. The director of the play for many years has been David Turner.