Many antiquarians, indeed, hold that the Cambridge of early days (anyhow down to the ninth century) was wholly confined to this small area, some quarter of a mile square, and that the extension of the town across the river was due to the expulsion of the inhabitants by Danish and Norman intruders. Be that as it may, we are here undoubtedly in the earliest Cambridge. The Castle has gradually passed away, till no ruins, even, are now left. Its modern representative, the County Court-house, where the Assizes are held, and the County Gaol, stand at the western foot of the great mound, whereon the Norman Keep no longer rises. From the summit is to be obtained a delightful view of Cambridge, with the "green-muffled" ring of the Backs, and the grey inner ring of the river-side Colleges, dominated by King's College Chapel, girding in the western flank of the Town, and starting almost from our feet; the long line of the East Anglian heights bounding our southern and eastern prospect; and to the north the "boundless plain," with the towers of Ely on the far horizon. Close below us, and really at our very feet, rise the two churches of this earliest Cambridge, that of St. Giles, now merely a handsome modern edifice of imposing size, and that of St. Peter, also modern in its present form, but embodying some ancient features. It is the smallest church in Cambridge, only thirty-five feet in length by fifteen in width, being the reconstructed fragment of a larger structure built in the twelfth century, and pulled down in the eighteenth, when the Parish was united to that of St. Giles. It contains a fine late Norman font, with grotesque figures at each corner--two-tailed Mer-men, each grasping his tails in either hand. At one time the Borough had yet a third church, "All Hallows by the Castle" (so called to distinguish it from "All Hallows in the Jewry"), but this has wholly disappeared, Parish and all. [Illustration: _Remains of St. Radegund's Priory._] Beyond the spire of St. Peter's, as seen from the top of Castle Hill, may be distinguished a small mediaeval building, known, for some forgotten reason, by the high-sounding title of "the School of Pythagoras." This lies just off the street to the eastward, at the point where this ceases to be a street, and merges into the open road that runs along the Backs. It is worth seeking out, for it is a picturesque little edifice, and an interesting example of a twelfth-century house built of stone. Wood, or, at the best, brick, were the materials then commonly used. In spite of the name, there is no reason to suppose that it was ever used for scholastic purposes, or anything more than a mere private dwelling-house. But Walter de Merton, the founder of Merton College, Oxford, actually acquired land hereabouts, apparently with some idea of starting a sister establishment at Cambridge. This land still belongs to Merton.