This is probably a rather odd question, but I live in an area that's fairly heavily mined (Flintshire) and on a quiet still night when you're sat out the back, I swear I can hear water dripping, as though it's falling quite some distance into a big pool.

I've heard that there is a big cave underneath this hill (Trial Hill), is it possible that I'm actually able to hear water falling inside the cave?

Or am I just going mad? 

If I really am hearing water falling inside the cave, does that mean that the layer of rock between me and a great big hole in the ground is actually really thin? ... it's limestone around these parts, so could the cave roof be getting thinner and thinner ... is it safe?

I've been doing a bit or research and found this: http://www.ucet.org.uk/index.php/forum/21-knowledge-bank/885-murphy-s-pot

However, from the description, I think that's talking about the path from the top of the hill that leads down to the leet path, I live right by the leet path as it crosses Cilcain road.

I once found a cave, Twll Gwynt Oer, by hearing running water at the bottom of a small dry shakehole. A 10 vertical dig led to a stream passge ending in a sump.  The shaft was totally filled and the small stream was running in a bedding plane to one side. I am sure that many finds have been made in a similar manner.

Jopo

Looks like you're not too far from Poachers Cave and Ogof Hesp Alyn, although I guess you are at the top of the hill and a bit nearer the bridge.

There certainly should be more cave to find here and it's entirely possible you have cave nearby.
Have you posted on the UCET forum? You will certainly get some intrest and I know at least one member of UCET lives probably less than 1/2 a km from you in Pantymwyn...

At least I'm not going barmy then ... or at least more barmy!

Your tip about poachers cave led me to this image:


https://44d18053-a-62cb3a1a-s-sites.googlegroups.com/site/cavesofnortheastwales/18-caves-p---s/OHA%20area%20DONE%20D%20%28Custom%29.jpg?attachauth=ANoY7crhMFyuIIt2FlCTtwdtHSFbYWcu7Y7neztK0nVc1h6qAgkV2DIUeWh5qf_uE9sH7wJyNsKQFweNV-t89B4FMF9gcCLE4VDc-XxqbtQl15-g0R3K-h-UIrjmJxzVL0QmLnpogUt4lqk2HNHzyk2bxCoeQ62Iozw2AG_rWxrnHWxXAGCKQ2aSjZbwDAn-CqNm6ztLseDNgaaM54iQnQv0bD6c9txxqX1ExtMm4fvtXsuJWTJwsVMARQp66fKECFifMU0dWeooTkhfJHGth-6qIXj_AnTSfQ%3D%3D&attredirects=0

I live to the left of where it says 'dome chamber' but to the right of the yellow markings for poachers cave

Cross-linking: http://ucet.org.uk/index.php/forum/29-say-hello