Caistor camp is a really satisfactory example of a Roman fortified _castrum_. For one thing, it has the largest area of any known relic of its kind in England, enclosing thirty-seven acres. If its fragments of flint walls have neither the thickness nor the height of those at Portus Rutupiæ, the old Roman port in Thanet, now known as Richborough, its deep ditch and massive embankment assist the laggard imagination of the layman in matters archæological, which refuses to be stirred before mere undulations in the sward. Here is a ditch that can be rolled into, an embankment that can be climbed and paced on three sides of the camp, if necessary, to put to physical test both height, depth and extent. The fourth side of this great enclosure, now a turnip-field, was bounded by the River Tase and was sufficiently defended by that stream, then a wide creek, so that no works are to be found there. How long it was before the Romans subdued the Iceni, whose great city is thought to have stood where Norwich does now, is not known. Nothing of that early time here, indeed, is _known_, and guesses are of the vaguest. Only it seems that the Roman advance into East Anglia, which had for its objective the principal stronghold of the tribes, here came to its military ending. To compare things so ancient and romantic with others modern and thought prosaic, the several Roman camps on the advance from London now to be sought at Uphall near Romford; Chipping Hill, near Witham, Lexden, and Tasburgh, are, with those that have disappeared, to be looked upon in the same light as the wayside stations on the railway to Norwich, a railway which originally came to a terminus at that city, and was only at a later date continued northward. [Illustration: THE OLD BRICK POUND.]