Having made Wales one of my areas of expertise with aardvark a request came in a few days ago asking for an itinerary for a four day transit to Holyhead. I came up with the following and decided to share it here.Given that you are heading for Holyhead it makes sense to come through midWales and spend time in the North, saving the South for another day
I would come into Wales by crossing the River Severn on the old bridge (the M48) and make Chepstow your first port of call. The Castle here is one of the most impressive in Wales. You then follow the river Wye to Monmouth stopping to look round Tintern Abbey which is one of those magically peaceful places even when full of tourists. The drive up to Monmouth is a delight and I recommend the Brockweir Inn for lunch if you have made an early start. Monmouth is a great market town and a good place to stay for the night,
Head for Abergavenny.
Just out of Abergavenny you can visit Tretower Court
(14th C Court Yard House) then up the A479 and A470 towards Rhayader which is charming and the views on this drive are all good. And in Rhayader you can take a side trip to the Elan Valley. But I would carry on to Llanidloes and then take the mountain road (B4518) past Llyn Clywedog with a good chance of seeing Red Kites. Turn left a mile or so out of Staylittle heading for Machynlleth. This is a longish drive through some spectacular scenery. When you get there, Machynlleth is a wonderful place, lots of old shops and a big alternative new age community as the Centre for Alternative Technology
(also worth a visit ) is nearby on the A487 which you will follow to Dolgellau. All diets from vegan to Welsh Black steaks available! Stay in either Machynlleth or Dolgellau. If you want to take a a day for a mountain walk then the bed ascent of Cadair Idris
is from this road (I can give you details) but it will take a day.
From Dolgellau take the coast road to Barmouth and then Harlech for another spectacular castle and thence to Blaenau Ffestinog which would allow you to visit the slate mines
to the north on the A470 – strongly recommended. There is also a narrow gage railway
to experience. You are now set on a spectacular drive through Snowdonia via Dolwyddelan (a native Welsh Castle not an English one) to Betwys y Coed which is a tourist trap but good nevertheless. Thence to the old coach road (the A5) to Capel Curig. Here you can complete on the A5 if you are running short of time, or divert via Llanberis for the best Mountain views.
You end up at Bangor, where you should come of the main road and take the old Menai Bridge not the new one. However I would consider diverting to see Caernafon Castle and the adjacent Roman Fort. If you can make the time then go down to Aberdaron and arrange a trip out to Bardsey Island
(where a thousand saints are buried). All possible if you are on the midnight ferry. Otherwise if heading for the ferry with less time turn left after the bridge and look over the Marquis of Anglesea’s mansion
which is open to the public. and from there take the coast road via Aberffraw (once capital of Wales) and Rhosneigr (great beach) to Holyhead.
Worth getting a Cadw card if you are visiting a lot of their sites.