(a) Promontory forts, or cliff castles both upon the coasts and inland.
(b) Those depending upon rivers, woods, marshes, etc. for efficiency.
(c) Plateau forts.
(a) Promontory Forts.—This type of fort is prehistoric as a rule and not characterised by an excess of variation. No distinctive uniformity can be traced, it is true, but special features may be discovered in almost every example of the class. It is only natural that primitive man should seize upon any spot which promised the minimum of labour to adapt it for his purpose of protection, hence distinguishing features may be discerned in almost every case, depending upon the presence of a precipice, slope, bog, wood, chasm, marsh, etc. The description of a few of these fortresses will sufficiently illustrate the point.
Trevalgue Head, one mile north-east of New Quay, is practically an island, being cut off from the mainland by a chasm through which the tide flows, thus presenting a formidable obstacle 20 feet wide in places. In order to strengthen this natural obstruction many lines of entrenchments have been thrown up, both upon the island and the mainland. The presence of quantities of flint chippings sufficiently proves that this fort was the residence of Neolithic man, probably the descendant of local Palæolithic ancestors.
As the terms "Stone Age," "Bronze Age," "Iron Age" do not convey any idea of date to the great majority of people, it may be advisable to mention that the Stone Age approximately terminated about 3000 B.C. upon the Continent, and 1500 B.C. in the British Isles, when the Bronze Age is supposed to have commenced. These dates are of course entirely conjectural. The Iron Age commenced in Britain about 400 B.C.
The general idea of a cliff castle may be gathered from the foregoing description of Trevalgue; there are many examples to be found in our Islands, and similar ones occur in Brittany. That they are of ancient British origin is suggested by the fact that they invariably occur in a district where cromlechs, stone circles, menhirs, and other Celtic remains are to be found.
Treryn Castle, about three miles from St. Buryan, contains the famous Logan stone. The fort is a gigantic mass of granite, nearly 250 feet in height, separated from the mainland by a triple row of formidable entrenchments, still 4 or 5 yards in height. This fort is probably the finest to be found in Cornwall.
At St. David's Head is a cliff castle called Clawll y Milwyr, where a small peninsula has been converted into a formidable fortress by the erection of a great stone wall about 12 feet in thickness and still some 15 or more feet in height. The only method of approaching the enclosed space is by a narrow entrance at the end of the wall. A fosse is associated with the defence in question, and several other subsidiary walls and fosses are found. Excavation has proved that the formation of the castle occurred in the early Iron Age.
MAIDEN CASTLE, DORSETSHIRE.