Close to Penrith is another circle called Mayborough, of about the same dimensions--100 metres--as that at Little Salkeld, but of a very different construction. The vallum or enclosure is entirely composed of small water-worn stones taken from the beds of the Eamount or Eden rivers. The stones are wonderfully uniform in size, and just about what any man could carry without inconvenience. This enclosure mound is now so mined that it is extremely difficult to guess what were its dimensions. It may have been from 15 feet to 20 feet high, and twice that in breadth at its base. The same cause makes it difficult to determine the dimensions of the internal area. The floor of the circle I calculated as 290 feet from the foot of one slope to the foot of the opposite one, and consequently the whole as from 320 feet to 340 feet[151] from crest to crest; but these dimensions must be taken as only approximative till a more careful survey is made than it was in my power to execute. Near, but not quite in the centre, stands a single splendid monolith; it may be 12 feet in height, but is more than twice the bulk of Long Meg. In Pennant's time there were four stones still standing in the centre, of which this was one, and probably there may originally have been several more forming a small circle in the centre.[152] In his day also he learned that there were four stones--two pairs--standing in a gap in the vallum looking like the commencement of an avenue. The place, however, is too near Penrith, and stone is there too valuable to allow of such things escaping, so that nothing now remains which would enable us to restore this monument with certainty. Close by this is a third circle known as Arthur's Round Table. [Illustration: 29. Sketch Plan of King Arthur's Round Table, with the side, obliterated by the road, restored.] It consists, or consisted, of a vallum of earth, as near as can be made out, 300 feet from crest to crest; but about one-third of the circle being cut away to form a road, it is not easy to speak with certainty. Inside the rampart is a broad berm, then a ditch, and in the centre a plateau about 170 feet in diameter, slightly raised in the centre. No stone is visible on the surface, though the rampart when broken into shows that it is principally composed of them. There is now only one entrance through the rampart and across the ditch, but as both entrances existed in Pennant's time (1772), and are figured in his plan of the monument, I have not hesitated to restore the second accordingly.[153] The distance between Mayborough and King Arthur's Round Table is about 110 yards, and at about the same distance from the last-named monument, a third circle existed in Pennant's time. It seems, however, to have been in his day at least only a circular ditch, and has now entirely disappeared.