St Martin-in-the-Fields is the neoclassical church facing Trafalgar Square, just across from the National Gallery. Its position puts it in the middle of central London foot traffic, but the building is more than a backdrop to the square.
The church is known for its music, its work with homeless Londoners, and its long civic role at the edge of the West End. Step inside if you are nearby, especially if a concert or rehearsal is underway.