If you want to commune with the spirits of Vivien Leigh, Noël Coward, Edith Evans, or Charlie Chaplin, this might be just the place. Memorials to them and many other theater greats are found in this 1633 work of the renowned Inigo Jones, who, as the King's Surveyor of Works, designed the whole of Covent Garden Piazza. St. Paul's Church has been known as "the actors' church" since the Restoration, thanks to the neighboring theater district and St. Paul's prominent parishioners.
(Well-known actors often read the lessons at services, and the church still hosts concerts and small-scale productions.) Fittingly, the opening scene of Shaw's Pygmalion takes place under its Tuscan portico (you might know it better from the musical My Fair Lady, starring Audrey Hepburn). The western end of the Piazza is a prime pitch for street entertainers, but if they're not to your liking, you can repair to the serenity of the garden entered from King or Bedford streets.