St James's Church, Piccadilly is a Christopher Wren church from 1684, set just off one of central London's busiest streets. Its best details include the organ case and baptismal font by Grinling Gibbons, whose wood carving is among the finest of the period.
The church is easy to visit while walking between Piccadilly, St James's, and Soho. It is a calm, compact stop rather than a headline London sight, but the architecture and craftsmanship make it worth stepping inside.