The Marble Faun, Volume I by Nathaniel Hawthorne

After Donatello had left the studio, Miriam herself came forth, and taking her way through some of the intricacies of the city, entered what might be called either a widening of a street, or a small piazza. The neighborhood comprised a baker's oven, emitting the usual fragrance of sour bread; a shoe shop; a linen-draper's shop; a pipe and cigar shop; a lottery office; a station for French soldiers, with a sentinel pacing in front; and a fruit-stand, at which a Roman matron was selling the dried kernels of chestnuts, wretched little figs, and some bouquets of yesterday. A church, of course, was near at hand, the facade of which ascended into lofty pinnacles, whereon were perched two or three winged figures of stone, either angelic or allegorical, blowing stone trumpets in close vicinity to the upper windows of an old and shabby palace. This palace was distinguished by a feature not very common in the architecture of Roman edifices; that is to say, a mediaeval tower, square, massive, lofty, and battlemented and machicolated at the summit.

At one of the angles of the battlements stood a shrine of the Virgin, such as we see everywhere at the street corners of Rome, but seldom or never, except in this solitary, instance, at a height above the ordinary level of men's views and aspirations. Connected with this old tower and its lofty shrine, there is a legend which we cannot here pause to tell; but for centuries a lamp has been burning before the Virgin's image, at noon, at midnight, and at all hours of the twenty-four, and must be kept burning forever, as long as the tower shall stand; or else the tower itself, the palace, and whatever estate belongs to it, shall pass from its hereditary possessor, in accordance with an ancient vow, and become the property of the Church.