Among these peculiarities, the most easily recognised are the square or oblong enclosures which surround tumuli, and, sometimes, one, at others two, or even three free-standing dolmens. In order to make the point clear, I have quoted a diagram from Sjöborg, though it is almost the only instance in this work in which a woodcut does not represent a really existing object. I have no doubt, however, that it is correct, as old Olaus Wormius represents one of two similar ones which in his day existed near Roeskilde. Both had enclosures 50 paces square, enclosing one tumulus with a circle of stones round its base, another halfway up, and, the text says, an altar-dolmen on the top, though the woodcut does not show it. The other, on the road to Birck, in Zeeland, enclosed three tumuli in juxtaposition, the one in the centre similar to that just described, and with a dolmen on its summit; two smaller mounds are represented in juxtaposition on either side, but with only a circle of stones round their base.[359] Other varieties no doubt exist, but modern antiquaries have not favoured us with any drawings of them. From the diagram and description it will be perceived that in so far as the mound itself is concerned these Danish tumuli are identical with those already quoted as existing in Auvergne (woodcut No. 8), but so far as I know, the square enclosure does not exist in France, nor does it in this country. These square enclosures seem, however, to belong to a very modern date, and the stones, consequently, are small, and may therefore have been removed, which could easily be done; but still there seems little doubt that many of them may still remain, and could be found if looked for. [Illustration: 110. Dolmen near Lüneburg. From Bonstetten.] One of the most striking examples I know of, an oblong rectangular enclosure, enclosing a single free-standing dolmen, is that near Lüneburg, figured by Bonstetten[360] (woodcut No. 110); he seldom, however, indulges in dimensions, and being perfectly convinced that all are prehistoric, he never speculates as to dates, nor condescends to notice traditions. What we know of it is therefore confined to the representation, which after all may be taken from some other work, as he rarely favours us with references. Two others are represented by von Estorff as existing near Uelzen, in Hanover.[361]