He fixes the periods as follows:—
| B.C. 2500-2000 | Copper and Stone. |
| B.C. 1900-900 | Bronze. |
| B.C. 800 | Iron Age. |
Now the Stone Age preceded that of Copper. So we must throw back the period of this vast forest to something like three thousand years before the Christian era.
Those who are satiated with the study of the tripper and the holiday-takers, and can wrench themselves from the contemplation of their sportive gambols, will take the train to Tal-y-cafn and walk thence to Caerhun, that occupies the site of the Roman town Conovium. This town did not give its name to the Conway, but took its title from it.
The Dulyn is a tributary of the Conway at Tal-y-bont (the Head of the Bridge), and it flows from the little lakes Llyn Dulyn (the Black Pool) and Melynllyn (the Yellow Pool), the former under fine crags, and forms a beautiful fall on its way.
Another stream, Afon Porthlwyd, issues from a much larger lake, the Llyn Eigiau, lying 1,220 feet above the sea under precipices of rock; and another again, the Afon Ddu, or Black River, rises in a still larger lake, the Llyn Cowlyd.
At Pen-y-Gaer, above Afon Dulyn and the little church of Llanbedr-y-Cennin, is a prehistoric camp of stone, with obstacles set in the soil, stones planted on end on the glacis, so as to break up an onrush of the enemy, in a manner seen in the Aran Isles off Ireland, some castles in Scotland, and one in Brittany. Where upright stones were not erected, sometimes the slope before the walls was purposely strewn with rubble or slates, and the assailants had to stumble over these slowly and with difficulty, exposed to volleys of arrows or stones, before they could come to close quarters. In some of the camps are great cairns of stones of a handy size piled up to serve as a store of missiles for the besieged.
It has often been remarked that these camps are away from springs and watercourses; and one wonders how those who held them managed for drink. But almost certainly they never were intended to stand long sieges. They were places of refuge. When an enemy appeared or was signalled by beacons, the inhabitants of the valleys and plains fled to them, driving their cattle before them and carrying their poor possessions on their backs. The foe came on and endeavoured to storm the stronghold; if he failed to do this at once, he abandoned the attempt, and did not sit down before it to reduce it by starvation. In some camps there are underground storehouses rudely constructed of stones set on end and roofed over, where the treasures of the tribe were concealed.
There is a story in the Norse Saga of Örvar Odd, of how he and other northern Vikings came on just such a subterranean passage. A great flat stone lay over it, but he chanced to pull it up, and found the entrance. He went in, and found it full of women in hiding. One was so pretty that he took hold of her and tried to drag her out, but the other women, screaming, held her back.