Rhosydd isn't too hard to pick your way around, certainly not as labyrinthine as Cwmorthin. But having said that Cwmorthin has been mapped extremely well and Rhosydd has not so maybe a guide would be a good idea?
My advice for Rhosydd would be to make the No.9 adit your entrance/exit don't be tempted by the 'twll' that place will put you in hospital (as I discovered :thumbsup: )
https://www.aditnow.co.uk/Mines/Rhosydd-Slate-Mine_7/ - right hand side of the page, lowest of the three.
The survey includes the flooded and collapsed bits - everything below floor 9 is flooded and much of the eastern workings have collapsed.
Yes, best to enter the mine via the no.9 adit.
You'll (probably) struggle to get lost...! :o
The chambering to the west of the incline is pretty simple to explore - basically as long as you head back in the opposite direction, you'll come back to the main incline and the adit.
To get to the furthest western workings, you need a bit of height gain and then skirt the bottom of the twll. The incline (3-6) is very nice.
To the the east it's mostly collapsed, but there are a few things to see.
You probably don't need a guide - take a survey and if in doubt head back to the incline.
As above, the two twlls are worth mentioning:
Don't try getting down into the western twll unless you know
for certain that you are going down in the correct place!
Even if you do find the right place; or if you want to climb out of the twll, be very careful if it's raining / has rained as it's going to be slippery and a slight stumble is likely to result in trouble.
Don't go down into the eastern twll unless you are tired of life!
Hello again darkness, my old friend...