The existing remains of Lindum, though unfortunately much defaced by continuous occupation, fully corroborate this view. In the third and fourth centuries it was a kind of twin-city—the original “colonia,” about 37 acres in extent, occupying the brow of the hill, while the lower town, a sort of “annex” to the first, descended its slopes to the banks of the Witham. The original town must have been of great strength. Its northern and southern walls were about a quarter of a mile in length, and were each pierced by a gate—probably a double gate—through which the Ermine Street passed and bisected the city. The eastern and western walls were a little shorter—about 420 yards—and each had a gate in the centre, also probably double, with guard-rooms on each side of the central space. The walls were 10 feet thick and over 20 feet in height. Though obviously repaired at various times, it is likely that they were erected at the foundation of the colony, as the recent destruction of the unwalled Camulodunum would be a stern warning to the first colonists. A few fragments exist, none in a perfect state; but the inner face of the northern (now strangely called “Newport”) gate is still entire, though half buried in the soil, and is a unique monument of Roman rule in Britain. It consists of a central arch about 16 feet wide, which had two posterns, of which the eastern, though built over, still remains; the other was destroyed about a century ago. The gate was formerly supposed to have been single; but it stands 20 feet back from the neighbouring fragments of the wall; and an old engraving, here reproduced,[14] shows the remains of two arches on its northern side. Such double gates are a frequent feature in the stations on Hadrian’s Wall. The south and east gates were still standing at the end of the seventeenth century, at least in part. But the former, which was near the brink of Steep Hill, was pulled down soon after, though its eastern postern can still be seen within a house; while the latter, which stood just east of the Deanery, was only demolished in 1763. The western gate was accidentally discovered in 1836, buried beneath the high mound of the Castle. The arch was uncovered, and found to be of the same age as Newport; but it collapsed a few days later from the weight of the superincumbent earth, though fortunately not till the sketch of it here shown had been taken. From this it appears to have been exposed nearly as low as Newport without discovering posterns, which may have been absent from this gate, because no military road passed through it. Yet there were signs of a return wall, which indicate that the gate was double. The western wall followed the line of the Castle rampart and beyond it to the waterworks reservoir; the eastern passed under the chapter-house and the eastern transepts of the Minster.