The Castle Hill stands on a considerable space, its circumference measuring 984 feet. Three deep grassy trenches and two steep ramparts guard the foot of it, and the defenders at the summit found shelter in the deep cup-like depression, resembling the crater of a volcano. A bygone generation planted a clump of trees in this hollow, and they have now grown to noble and striking proportions. There was never at any time any building on this defensible earthwork, which was itself the “Castle.” The place stands in a beautiful spot on the eastern outskirts of the town, in the midst of noble trees and luxuriant turf. Unlike the great majority of the prehistoric earthworks noticed in guide-books and in the learned papers of archæological societies, it is generally interesting, and appeals to the eyes even of those uninstructed in archæology. [Illustration: CASTLE HILL, THETFORD, IN 1848. _From an old print._] [Illustration: CASTLE HILL, THETFORD.] That the Castle Hill was built for defence there can be no doubt, and its height, its steep sides, and the defensive earthworks that describe a rude half-circle around it give the measure of the fear its unknown builders had of their unknown enemy. They who reared these works were terribly scared. That enemy was evidently expected to come out of the south, for the great mound stands on the northern side of the rivers and marshes which then spread over all the neighbouring flat meadows; and the horns of the semicircular ditches and ramparts at that time touched those kindly frontier waters. The Icknield Way, already traced to the “Nuns’ Bridges,” came across that watery waste and pursued its course into Norfolk under the shoulder of the mysterious mound. XXXVI