The observations of Mr. Gwilt relative to the Church of St. Mary-le-Bow, in the City of London, and its Saxon or Norman Crypt, published in the fifth volume of the Vetusta Monumenta, with the very accurate illustrative Engravings, excited much interest in relation to the structure; but it is not generally known that there exist, in its immediate neighbourhood, subterranean architectural remains, although evidently of a later date, yet of a very interesting character.