The megalithic monuments of Mecklenburg are supposed to date from Neolithic times, and are constructed in two very different ways. The _Hünengräber_, formed of huge blocks of granite set up at right angles to each other, resemble the covered avenues of France and elsewhere; in the so-called _Riesenbetten_, or giant’s beds, on the contrary, the sepulchral chamber is merely sunk in the ground. We must also mention the so-called _Grotte des Fées_, or fairy grotto, forming part of so many of the megalithic monuments of Provence. This fairy grotto includes an open-air gallery cut in the mountain limestone and roofed in with huge flat stones. This gallery leads to a sepulchral chamber not less than seventy-nine feet long. The stones used for the covered avenue of Mureaux (Seine et Oise) carne from the other side of the Seine, so that the builders must have crossed the river in a raft. Excavations have brought to light several skeletons that had been buried without any attempt at orientation, the bores of which were still in their natural position. The objects found in this tomb were very numerous mid belonged to the Neolithic period.18 We have now specified the chief forms and modes of arrangement of megalithic monuments, and must add that they are often found in juxtaposition. At Mané-Lud, for instance, on a rocky platform which had been artificially smoothed, and which is some 246 feet long by 162 in area, we find at the eastern extremity an avenue of upright stones, on the west a dolmen, and in the centre a crypt surmounted by a conical pile of stones. Between the cone and the avenue the ground is covered with an artificial paving of small stones cemented together, and known in France as a _nappe pierreuse_, and amongst the stones forming this paving were found quantities of charcoal and bones of animals. The megalith was completely buried beneath a mound of earth, or rather of dried mud, the amount of which was estimated at more than 37,986 cubic feet. At Lestridiou (Finistère), a cromlech forms the starting-point of an alignment formed of seven rows of small menhirs, the mean height of which above the ground does not exceed three feet; and these alignments lead up to two covered avenues and a central dolmen. In other cases, in England and the land of Moab for instance, alignments simply lead to cromlechs; whilst in some few cases, as at Stennis (Fig. 63), the menhirs are scattered about a plain in great numbers, with nothing either in their form or their position, or in the traditions relating to them, to throw the slightest light on their origin. [Illustration: 63.] Monoliths at Stennis, in the Orkney, Islands.