Driving to Snowdonia from Heathrow

if the plane lands on time at 9AM, assuming it and you are from USA, you will be lucky if you start the car before 12. Driving at that time will take 4.5 - 5 hours by fastest route without breaks - and the problem with that is that it uses the least amount of welsh roads, you'll see more of Birmingham and the west midlands metropolitan area than Wales! To use the old main route which crosses Wales will take around 2 hours more (and you'd definately need a break). That would be bad enough but you will probably be jetlagged. It just isn't viable.

What might be suitable is to go to somewhere in the Welsh borderlands from where you could make a round tour of Snowdonia on the Friday, this would also make Saturday much easier. Llandrindod Wells in Wales or Shrewsbury on England would fit this itinery.

Late-September bus and train schedules may be thin enough to make this impossible for you, but I spent several August nights in Chester (touristy but very handsome English town). One day I completed this route:

Regular train to Llandudno Junction
Regular train to Blaenau Ffestiniog (the most scenic section)
Historic train to Porthmadog (the next most scenic section)
Historic train to Caernarfon
Bus to Bangor
Regular train to Llandudno Junction
Regular train to Chester

Even if the schedules hace changed enough to make the loop impossible, you could certainly do a round-trip to Blaenau Ffestiniog, at least. There would probably be enough time for a quick side trip to Conwy, but you might be seeing it in the dark.

There might also be a bus tour out of Chester.

But the weather warnings are spot on. Clouds, rain and fog are all very possible. You could spend £200 or more and see basically nothing of Wales.

Hmm. So north Wales is pretty much out of the question. Good to know. I thought so, but someone had suggested it so I wondered if I was off base. Thanks for the advice. I will check out the mid-Wales area, or perhaps just head to Gloucester, and day trip into Wales on Friday...

You have to fly out of Stansted - which is on the other side of the country to north Wales. So, it is not just about getting from Heathrow to North Wales but also getting back across the country to Stansted. I would rule Wales out. Consider staying in Suffolk - which has some lovely villages.http://www.visitsuffolk.com

Brecon Beacons National park is a lovely mix of low mountains, castles, and sheep, and it doesn't seem insane to take a train from Heathrow to Cardiff by way of Paddington station, pick up a rental car in Cardiff, and use that as a base to explore the park.