James Gibb's church, St. Martin-in-the-Fields, is in the northeastern corner of Trafalgar Square. There has been a church on this sight since the 13th century; the present building was completed in 1726. Its magnificent Corinthian portico has been much copied in the US where it became a model for the Colonial style of church building.
St. Martin-in-the-Fields is the official parish church for Buckingham Palace. Inside, there is a royal box on the left of the alter and one for the admiralty on the right.
There is a shelter for the homeless and a very good cafe in the crypt, as well as the London Brass Rubbing Centre.