Situated a hundred feet or so around
the corner of Ness Point at St Margaret's Bay, above the high water
mark, is the entrance to a natural tunnel through the cliff extending
over 500'. Although not particularly dangerous in itself there is the
possibility of being cut off by the tide for long periods of time. If
intending to visit I would strongly suggest checking the state of the
tide first. Due to the physical properties of the tunnel I would also
suggest that exploration should NOT be attempted by anyone of generous
girth or a tendency towards claustrophobia! Although some of the
system is navigated on hands and knees, in many spots there is
insufficient room to do anything other than wriggle along very
uncomfortably.
The report below, and the plan of the cave, are courtesy the Chelsea
Speleaological Society and T. Reeve, reproduced with their kind
permission.
"This interesting cave received a great deal of attention from C.S.S.
during the winter of 1975/6. The only previous written reference
located to date is the name “Canterbury Cave” on a sketch map of the
South Foreland by R.H.A.Staniforth. Apparently this is a local name
for the cave.
The cave entrance was also noted by the author in 1965, but was not
fully explored at the time as the passage went beyond the limit of
daylight penetration. Thus it was not until November 1976 that its
significance was realised, when it came as something of a surprise to
find a cave system of unsuspected extent.
This cave cannot have resulted from sea erosion as it is above the
normal range of tides. The cliff appears to have exposed an existing
fossil cave system originally formed by Karst drainage, similar to
those in Northern France. Just how much cave has been eroded on the
seaward side is a matter for conjecture.
It is entered by clambering over various boulders into a chamber which
has been enlarged by roof falls resulting from marine erosion during
exceptionally high tides. This chamber was probably formed at the
confluence of two former passages, now eroded away on the
seaward-side. The last few feet of these passages were still
discernible in 1965, when there were two openings leadine into the
chamber, separated by a pillar of chalk which has since collapsed.
At the rear of this chamber a passage averaging 7ft. in width and 4ft.
in height extends into the cliff in a north—west direction. It is
floored with a collection of flint nodules and solutionally—eroded
chalk rubble. Progress is mainly by hands and knees crawling. 8Oft.
from the cliff face the passage bends to the right, assuming a
northern direction and opening into a small chamber, 3Oft. long, up to
l2ft. wide and up to 5ft. high, before resuming the north—west
direction after a sharp left turn.
Any doubts on the origin of the cave are cast aside on entering this
chamber; the roof and walls are covered with scallop markings; flints
and fossils protrude from the solution eroded chalk; joints have been
picked out by solution, and at floor level on the right hand side
there are a number of tube—like openings up to 9ins. in diameter.
About 5Oft. beyond the chamber, the passage veers to the left and
becomes a flat—out crawl for about 2Oft. The crawl ends in the form of
a T—junction with a roomier north—trending passage. The obvious way on
is to the right and after a few yards in this direction, a
dissolved-out joint is seen crossing the passage at right angles.
Beyond this point the passage is strewn with large boulders which have
obviously fallen from the roof. Most of these boulders show evidence
of solutional erosion, and the same can be said of their original
locations between two parallel joints in the roof. So it seems likely
that most of this breakdown occured when the cave was actively filled
with water. After crawling over and around various boulders for about
7Oft. the cave appears to end in an impenetrable fissure, but closer
inspection reveals a way on to the left and a short flat—out crawl
leads to another stretch of roomier passage, which terminates choked
with rubble and boulders, just over 500ft. from the entrance.
It is quite possible that the passage continues beyond this choke and
there would seem to be some prospect of passing the obstruction by
careful digging.
Returning to the T—junction, the passage continues southwards, but
rapidly diminishes in size, and is almost choked to the roof with
sediment, apparently derived from the Thanet Sand. The passage was
eventually pushed in this direction for about 45ft. by deepening the
floor and, during the exploration, a number of rat and rabbit bones
were unearthed. The roof showed evidence of being heavily eroded, with
rounded pockets etched out along the joints. At the furthest point
reached, the way ahead was completely choked, but a narrow rift could
be seen on the left, with rounded solution pockets in the roof. The
total length of the cave is 550ft. The passages are obviously
joint—orientated, but there is another less obvious feature that may
have played a major part in the formation of the cave, and that is the
tabular flint layer seen beneath the rubble floor near the entrance.
In the cliff face nearby the chalk above the upper surface of the same
flint layer is honeycombed with tubes only a few inches in width —
forming, in effect, a micro—cave system. It is also interesting to
compare the cross— sections with those of a cave found under Strood
Waterworks which also show a tabular flint layer at floor level.
Further examples of caves floored with tabular flint can be seen
sectioned in the cliff near Beachy Head. These flint seams may have
formed a waterproof layer resulting in a perched phreatic zone above
the general level of the water table.
The cave was surveyed during two visits during 1976 by T. Reeve, Dave
Parkyn and Phil Dinn. A fibron tape measure was used and bearings
taken with a prismatic compass. Offsets from the survey line were
taken at intervals of 5ft. The survey meets the requirements of BCRA
Grade 5d.8"
To see the full size
pictures, right click than click on go full size.
Access is not possible, this is on
private land.