St Peter's (1721-1724), a charming little church of dark brick, was originally a chapel for the inhabitants of Cavendish Square. The church is adorned with stone quoins which emphasise the corners of the building, a square tower and an open belfry. Designed by the architect James Gibbs, it was probably an experimental model for the church of St Martin-in-the-Fields. The church now houses the Institute for Contemporary Christianity.