From the A5 take the B4366 towards Llanberis after approx 2.6 miles take the right hand turn signposted for Caerhun. There's a decent pub on the left called the Vaynol that does a nice meal.
Cross over a small stone bridge. Here the road will fork off to the right, don't follow this but turn left onto Pont Felin which is a single track road. (there was some mad classic car race taking place on these back roads on my last visit).
Approx half mile along this road there is a small stone bridge on the left leading to a field. Park your car (if you are in one) just after this bridge.
Cross over this bridge. The farm gate may be closed but isn't usually padlocked. The first standing stone can be seen directly infront of you.
The RCAHMW give this ref for this site NPRN
The farm of Ty'n-Llwyn is surrounded by a rough circle or oval setting of 6 standing stones and two mounds. The setting encloses a considerable area of approximately 750m diameter. The discovery of an interrupted ditch enclosure or plough-levelled barrow (NPRN 403377) during RCAHMW aerial reconnaissance in 2005, with a (then unrecorded) standing stone on its summit, gave context to the stone; it seemed as likely to be a prehistoric ritual monument as a modern boundary stone.
A prehistoric date for the remaining stones in this 'setting' would be highly unusual given its size. However, their ascription to being modern boundary stones does not explain the occurrence of a mound and a complex barrow within the setting.
There is an aerial photo of this taken by RCAHMW at this web site:
I have visited 2 more of the stones mentioned by Coflien. The next to go and see would be in the field to the right. Follow round the edge of the field next to the woodland. (be aware if you have dogs with you that this is a covert and is full of pheasants)
At the edge of the woodland continue following the field boundary. There will be a gate in the middle of the fence on your right. The next stone can be seen on a mound in the middle of this field.
If you look towards Tyn-llywyn farm you will be able to see another mound. There may be another stone on this mound.
Looking back towards the first stone you can clearly see the mound which that stands upon.
The CBA Wales gives this description of the first mound.
near Pentir, a plough-levelled barrow with a causewayed ditch and partial surrounding palisade was discovered (Figure 2; NPRNs 403376 & 403377). More problematic is the fact that the mound is surmounted by an undated standing stone, which forms part of a wider circle of stones and a levelled mound currently of unknown date, surrounding nearby Ty'n Llwyn farm. More work is needed to ascertain the true date and origins of these features.
And there is a diagram of the features at the following web address:
Once you have made your way back to the road turn right after you have crossed over the bridge. After a few metres you will see a gate on the opposite side of the road. You will have to climb this one. Walk around the boundary of the field to the top. The next stone is at the top of the field on the right.
We did find another stone lower down the field but this was surrounded by farm machinary.
I then found that there was an arrow sharpening stone just down the same road at Rhos Fawr. PRN 33 SH56086833 but had no luck in finding it depite my best efforts and with the only outcome being a very sore back, scratches and insect bites.
We found where it should be, but the vegetation was just too dense to have any success.
Would be a great find. But may be one for winter.
G.A.T says of this
Primary Reference Number (PRN) : 33
Trust : Gwynedd
Site Type : ARROW SHARPENING STONE
Period : Unknown
Community : Pentir
NGR : SH56086833
Legal Protection :
A large boulder with as many as forty-five sharpening marks was discovered during fieldwork along the line of the Pentir Llanfairpwll gas pipeline in June 1976. The incisions were accompanied by an area impressed with small punch marks and patches of deliberate smoothing. The boulder was moved to the side of the pipeline track to avoid further disturbance. A total of 45 V-sectioned incisions were observed.
There is so much going on in this area. Still so much more to find.
Don't be put off by the blooming great electricity station.