] 02 Essay on Caerphilly Castle. 



from.tlie river Taafe to the Rhymny, on the west and east; includes within 

 its limits a vast basin, bounded on three sides by mountains, rather vast 

 than lofty, and terminating towards the east in a spacious valley, down 

 which, descending from the northern range, the river Rhymny, the boundary 

 of Glamorgan and Monmouth, takes its course to the Bristol Channel. The 

 scenery of these mountains is of that peculiar variety which characterises 

 what is called by geologists, the carboniferous formation. 



Along the base of these mountains, and extending some way up their 

 skirts, here, as in many vallies in the neighbourhood, lie vast deposits of 

 gravel and sand, composed of the debris of the neighbouring rocks, and 

 supposed to have been brought down by diluvial agency. 



Near the centre of the basin which we have described, and south-west 

 of the line at which it is crossed by the Rhymny, is a bed of this gravel, 

 of very considerable extent and thickness, the surface of which has been 

 wrought deeply, by some natural process, into a series of furrows and 

 eminences. 



A narrow tongue of slightly elevated ground, being the termination of 

 an extensive peninsula, divides by its projection a swam])y flat of con- 

 siderable breadth, into two unequal portions. The two plains thus sepa- 

 rated are contained, in the opposite direction, within irregular banks of 

 gravel, similar to, though something higher than, that of the central penin- 

 sula. The southern being shorter and almost parallel to it, while the 

 northern is prolonged and curves around its point, until it is separated 

 from the southern only by an inconsiderable gorge, and thus the swamp 

 assumes a shape something like that of a horse-shoe. 



South of the peninsula, between it and the soutiiern bank, a considerable 

 stream, the Nant-y-Gledyr, takes its course, and passing in an easterly 

 direction towards the gorge, becomes tributary to the Rhymny, at the 

 distance of about a mile. 



On the opposite side of the peninsula, a rivulet at first parallel to, but 

 smaller than the Nant-y-Gledyr, occupies a narrow depression between 

 the banks, which here closely approximate, and thus finds its way into the 

 lesser or northern swamp ; whence, coasting round the prolongation of the 

 peninsula, it seems anciently to have fallen into the larger stream at the 

 above-mentioned gorge. There is, however, evidence of a smaller branch, 

 whose channel diverged towards the north-east. 



The tongue of land which we have described, was in all respects admi- 

 rably suited for a barbarian encampment ; and there is strong reason for 

 supposing that the ancient castle of Senghennytli was nothing more than 

 a rude structure, erected upon this tongue, and defended by a transverse 

 trench, converting the peninsula into an island. Such a work would have 

 been perfectly in unison with the habits of the early Britons ; and the 

 supposition is borne out by a reference to other rude fortifications still 

 extant in the country. 



