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Ogof Clogwyn Letterbox Hybrid

Hidden : 06/25/2016
5 out of 5
5 out of 5

Size: Size:   small (small)

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Geocache Description:

This is my 200th cache placement and I wanted to do something a bit special!! So here it is!

Ogof Clogwyn (affectionately known as Cloggy to it's friends) is a well known cave in the upper part of the Clydach Gorge, or Cwm Clydach, situated between Abergavenny and Brynmawr in South Wales.

Thought of as a beginners cave Ogof Clogwyn is very well known in the area and most local cavers will very likely have been in it at least once during their caving activities. And for good reason too as it is regarded as having some of the best examples of phreatic rock shelving around (see below) which is present along much of it, there is water flowing it's entire length so visitors will most likely get wet at some point but a lot of the water can be avoided by traversing over it. It's simply a pretty cave in a pretty spot!


The Cache

This is my 200th cache placement! The small cache is situated at the far end of the cave and the general route description is below, along with a more detailed description of the precise cache location (which was a condition of the placement of this cache from Natural Resources Wales, so please make sure you replace it as found to keep out of sight of other cave users and to protect it for future geocacher visitors). There is a stamp and pad inside for you to you use but please leave in the cache as usual.

The Route

There really is only one main way in and out of Ogof Clogwyn which follows a passage that is at least head height all the way and no squeezing or crawling is needed (apart from the very short bit of easy crawl just at the entrance). If you need to squeeze or crawl then you have gone wrong somewhere!

So, you will need to jump up into the entrance where the water is flowing out and you will find yourself in the main passage. Simply follow this round to the right first of all and it meanders for a bit both ways and you will see light coming through two squeeze entrances on your right. Ignore these entrances and stay in the main passage which then turns 90 degrees left, this continues for about 30m then turns left again. After about 15m the passage turns right 90 degrees and left 90 degrees again. A short way on you will come to a fall of a couple of large boulders which you can either go under (and get wet) or over (and stay dryer) and immediately go right another 90 degrees (above this you will see a rift but I don't want you to go up there!)

Continue along the main passage for about 50m more, and you will see a crawl low down to the right that soon ends at a small sump, but again continue along the main passage and the roof gradually lowers to meet the water at a terminal sump. This marks the end of Ogof Clogwyn.

But to find the cache you will need to go back to the point just before the sump where the roof changes above you from smooth rock up to a higher rift ceiling (here you can see some flowstone up on the left if you are facing the way back out) and just to the right (still facing the way back out) at about shoulder level there is a small hole where the cache is hidden behind a stone. PLEASE COVER WELL WITH THE STONES AFTERWARDS SO THAT IT DOESN'T GO WALKABOUTS, AND LEAVE THE RESIDENT 'AMBEREL TOP CACHE GEOCOIN' (COPY) IN THE GEOCACHE FOR EVERYONE TO DISCOVER, MANY THANKS.


PLEASE NOTE: Caving, by it's very nature, has an element of risk and this cache is rated as a 5/5 for that reason - as such it is considered an 'extreme' cache due to the fact that you will be entering a cave and should only be attempted by those who have skills, knowledge and experience in caving and being underground, and have the appropriate equipment (and know how to use it!), or be accompanied by someone with said experience and skill.
Also, just because I have placed the cache in the cave does not mean that that cave is safe to enter, only that I was happy to enter it when I placed it. If you think it is not within your capabilities or experience or you do not have the correct equipment (and/or not know how to use it!) then walk away - the decision to enter the cave is entirely your responsibility as are the possible consequences.
However there are no climbs or pitches in this cave that you need encounter whilst on the way to or from the cache but it is always wet due to continuous stream flow (although it has not been known to flood).

I do not feel it appropriate to add an equipment list for this cache because if you do not know what you need or have it then you really shouldn't be in the cave.


I have provided a parking waypoint for you. Park here and walk up the small road in a north-west direction to pass a building on your right, just after this is a small footpath down to the right through a silver gate that runs next to an information board which you should take. This footpath can be slippery and muddy. Follow it until you reach some wooden steps which you need to follow down next to a rock face and at the bottom follow round to the left where you will find the cave entrance with it's small stream issuing from the entrance.

WARNING! The way-pointed track down to the cave can itself be rather dangerous due to it being damp and wet even in dry weather and people have had serious accidents on their way to and from the cave entrance. Because of this anchor points have been set up on the steepest parts and you may want to make use of them, especially in the wet.

If by any chance you do get into trouble in the cave then ring 999 and ask for 'Cave Rescue' or the police.
Many thanks to Natural Resources Wales who gave their kind permission for this cache to be placed.

Picture of cache

Additional Hints (Decrypt)

Qrgnvyrq uryc tvira va qrfpevcgvba. Cyrnfr yrnir erfvqrag Gbc Pnpur trbpbva va gur pnpur.

Decryption Key


(letter above equals below, and vice versa)