We stopped off at Usk on the way across the Heads of the Valleys before heading west again. Phil was staying with relatives down there so we met him at Aberdare Wetherspoons at 8am for a big greasy breakfast! We then started on what was an itinerary of 7 or 8 tunnels which we didn't complete because the unexpected happened... we got in Rhondda. Doing this monster of a tunnel took most of the day.

We did:

1. Usk: This is on a footpath and is open to the public. It is 256yds and unlit. There is evidence of subsidence at the east end where there are long cracks in the brickwork. The floor has been raised throughout with rough infill though a drainage channel has been left against each wall. The tunnel profile is a typical horseshoe shape except for a short section in the middle which is more rounded and may be the remnants of a collapse which took place in the latter stages of construction delaying the opening of this section of the line from June 1856 to October 1857.
2. Pen-cae-drain: Parallel to the A465. A good starter to prepare us for the main course...
3. Rhondda: We came to scout around. I wanted to see the legendary lump of concrete, I thought it might be the way in. Everyone else was championing the alleged 250m crawl along a drain as the way in. Well, neither of us was exactly right. The concrete has gone and... well, anyway, we got in!
   
   I had no fuel for my trusty Eccles Protector No.6 miner's lamp and being buried at both ends means the tunnel air could be bad (though there is a ventilation pipe leading from the top of the tunnel to the surface at the east end where the concrete block used to be. As the most common harmfull gases (Carbon Monoxide and Methane) are lighter than air, they should escape via this pipe). I was confident there would be no methane as there is no landfil and no mining activity. I was also confident that there would be no carbon monoxide as this is produced by incomplete combustion and there is no reason to believe there had been any explosions or fires down there. However, I could not be sure of a satisfactory level of oxygen in the air and this is where the lamp excels so we headed off to B&Q for a bottle of lamp oil. We managed to find one at the third B&Q and headed back. On the way to B&Q we looked in at Cymmer and Geli.
   
   When we got back the landowner was there. He was very good about us piling onto his land (we didn't know it was private, it looks public). He was none too pleased, though, that ( as he thought) we had broken the locks to get in. When he saw we had a key he was a bit more chilled but he does not want hoards of people turning up. He said that the first time the locks get broken he will get onto BRB(R) to have the access permanently sealed... so don't do it have respect for the guy (and borrow a key then go in the dead of night!).
4. Cymmer: Just a quick look at the buried north portal as we were passing over it anyway, we didn't do the tunnel.
5. Gelli: Single bore, 164yds and easy to access.