Travellers on the North-Western to Holyhead or Snowdonia are familiar with several cave mouths that form a prominent feature in the Limestone cliffs above Lord Dundonald's castle, near the station of Llandulas. The most conspicuous is a vast antre near the cliff-top; and legend has it that this opens into passages running for great distances, and eventually descending beneath the sea. (Welsh cave-myths are not less extravagant than those of Derbyshire and Somerset, where stories of dogs, geese, and other animals that have made long pilgrimages underground and come into daylight again divested of feathers or hair, are still piously cherished by the credulous.) The name attached to this group of caves, Tanyrogo—"under the cave"—is derived from the Celtic ogo or ogof, a cavern, and is almost identical with the original name of Wookey Hole in Somerset. A party of explorers from Liverpool and Colwyn Bay have recently carried out some researches in the Tanyrogo caves, and in those at St. George, on the other side of Abergele; and while verifying their disbelief in the supposed extent of the subterranean galleries, have ascertained many interesting facts as to the formation and the geological history of both series.

A grassy terrace runs along the cliff face to the gaping portal of the Ogo, the biggest of the Tanyrogo caves, which looks seaward and commands a magnificent view over the coast and the Irish sea. The prehistoric men who doubtless lived here once showed not only good taste in the choice of a site for their residence, but a judicious eye for military possibilities; the place is all but impregnable, save by starvation, the only access being by this narrow ledge, which a handful of men could defend against an army. Spanned by a noble arch is a colossal vestibule, rock-floored and dry. But this imposing entrance is a deception—there is nothing beyond to compare with its shape and magnitude. We swerved to the left, and at once found ourselves treading a floor of wet clay, which began to ascend, and soon steepened into a high bank leading up towards the roof. Creeping under an arch, we found ourselves in a transverse fissure that may have run as far as the legends pleased, but grew too narrow in a few feet for any human being to penetrate farther. A few rudimentary stalactites and a crust of pure white calcite adorned one small grotto; the rest was bare rock walls and rugged arches, springing here and there high into the darkness, in fissures that must reach very nearly to the summit of the cliff. A branch passage dwindled away still more quickly, and so did a minor opening that looks like a side door to the main entrance.

The rock structure of the cave arches is displayed in very beautiful ways in this cavern, but the most interesting feature is the remnant of an old cave floor. The cavern was evidently formed in pre-Glacial times, and the vast quantities of clay that plug it up almost entirely now must have been carried in by the ice. After the glaciers had receded, the normal agencies began their work again; a stalagmite floor was formed by the drip of water from the roof, depositing a layer of calcite; this in the course of time was broken down again, and now leaves a kind of high-water mark all round the walls of the cavity.

THE OGO, NEAR ABERGELE.

Photo by E. A. Baker.

INSIDE THE OGO, NEAR ABERGELE.

Photo by E. A. Baker.

The line of the fissure creating the upward chasms inside the cave can be traced in the external configuration of the cliff; in sundry vertical openings in the face, and in the clean-cut walls, where sheer masses have fallen away, broken at the joints. Similar joints and fissures played a part in the formation of a lower tier of caves, which we explored next. The first was only a yard or two wide, but very lofty, and its floor was composed of a level bed of sand and clay. This gradually rose as we walked into the darkness, until the cave ended more abruptly even than the last. We noticed pebbles of Bunter sandstone in the floor, and the next cave produced many more examples of the same stone, which must have been brought from a long distance, the nearest strata corresponding to it being in Wirral. At the back of this next cave a bank of cave earth and boulder clay was piled right up to the roof, so steeply that it was not too easy a climb to the summit. Arrived there, we found no possible egress; but a horizontal tunnel, a sort of squint or hagioscope probably more than forty feet long, gave us a peep through the rocky cliff out to the sunlight. We set out forthwith to discover the outside orifice of this curious hole, and found it came out on a ledge in the face of the cliff, hard by an open platform which had a very queer look about it. On examination this proved to be the floor of an old cave that had been destroyed by the quarrymen. Half-embedded in thick clay were a number of stalagmite pedestals, and a floor of stalagmite underneath several feet in depth, surmounting a thick bed of boulder clay stuck full of Bunter pebbles. It was obvious that the quarrymen, coming across this mass of useless material, had not troubled to attack the solid layer of stalagmite above it. The remains of stalactites and stalagmite curtains still adhered to the neighbouring cliff.

The spot is well worth visiting, if only to see this remarkable illustration of several consecutive chapters in the history of a cavern. The destructive work of the Limestone quarry, having been checked at this particular point, exposes the whole thing as in a diagram; and the actual evidences are there just as they were produced by the forces acting in successive epochs—the mouth of the original cave, formed perhaps in pre-Triassic times; the masses of drift thrust in by the glaciers; and the new cave floor, with its growth of stalagmites. Since the caves lie at a height of several hundred feet above sea-level, it is fairly certain that the moving glaciers exerted an upward as well as a horizontal force, shoving the plastic masses of clay and dÉbris into the ascending passages, and caulking up, no doubt, a good many tributary galleries that are now unknown. The caves look north, and the material pushed into them must have come from seaward; there is, furthermore, no rock in the adjoining districts that could have yielded this kind of pebbles: so that it appears the stream of glaciers which flowed across from Lancashire and Cheshire, impinging against the contrary flow of ice from Snowdonia, must be held responsible for the presence of these dense deposits. All along the meadow-lands between the Limestone hills and the sea a series of risings or big springs are noticeable from the railway, forming large pools. These are the outlets of the drainage that has been absorbed by the Limestone strata, through which the water has found its way until, meeting with an impermeable layer of rock, or reaching the plane of saturation at sea-level, it has been forced to the surface.

IN THE OGO, NEAR ABERGELE.

Photo by E. A. Baker.

The St. George's Caves are situated on and about a wooded hill of Limestone near the village, which adjoins the low-lying lands of Morfa Rhuddlan, the scene of a murderous battle in the year 795. The Celt, with his strong historical imagination, such a factor in national solidarity, still remembers, though confusedly perhaps, some incidents of that calamitous fight. The old woman who pointed out the situation of the caves drew our attention to the ditch and rampart which run round the hillcrest, where it is not protected by cliffs. There, she said, the routed Welsh tribes had entrenched themselves and fought desperately on until every man was put to the sword. The wood on the hilltop is full of graves, she told us, and weapons often come to light there.

A great master-joint or fissure runs across the hill towards the battlefield, and in it lie the caves, or rather the cave, for so far as we could make out they are all parts of one stream-channel. At the top of a cliff that is now being worked for lime is a small orifice, a mere fox's hole, blocked up against Master Reynard or the badgers that often find a home in these small caves. A hundred feet beneath it is a larger opening, which is said to give entrance into several good-sized chambers; but that also has been carefully built up with fragments of Limestone by the quarrymen. We were driven accordingly to seek the outlet of the cave, and this we found by following the smooth, straight escarpment, produced by the fault, in a wood close to the mainroad. A large stream once issued from the cave mouth, but has since become engulfed in some internal swallet, and emerges a few yards lower down, welling out from a funnel of crystal water some 15 feet deep. The cave itself discharges a stream only in flood-time. There, too, we were stopped from penetrating far by the beds of clay that gradually rose to the cave roof; but in this instance the deposits had been made by the stream, and were not the results of glacial action pushing upwards. In fact, this is a cave with quite a modern history, one still in working order, and used as a waterway at the proper times and seasons by the stream that made it. The Tanyrogo Caves, on the other hand, have ceased for untold ages to be actual water-channels, having been deprived long ago by denudation above and behind them of the greater part of their drainage area. And since that remote epoch they have gone through the series of vicissitudes so plainly recorded in their present physiognomy.

A PRE-GLACIAL CAVE, LLANDULAS.

Photo by E. A. Baker.