Castles and Gardens

Lets assume that you do your planned journey from Bath to Conwy via Tintern. The AA website tells us that this would be a 200 mile trip taking 4 hours 28 minutes (without stops). http://www.theaa.com/route-planner/index.jsp
So, it is doable. The main problem with their route is Hereford - which can take 20 minutes or so just to get from one side to the other as it lacks a by-pass. (It does contain an ancient cathedral).

The first thing to note is that Chepstow has a Norman Castle. (This is the first Welsh town you reach when crossing the M48 Severn Bridge from England). http://cadw.gov.wales/daysout/chepstow-castle/?lang=en
Then it would be a 20 minute drive up the Wye Valley to Tintern.

This place is between (slight detour) Hereford & Leominster:> http://www.hamptoncourt.org.uk

When progressing up the A49 between Hereford & Shrewsbury, I would definitely take a detour into Ludlow. This is real Ye Olde England and also has a Castle - best seen from the west bank of the river. http://www.ludlow.org.uk

Just north of Ludlow is Stokesay Castle - a fortified Manor House rather than a proper castle.http://www.english-heritage.org.uk/visit/places/stokesay-castle/

Shrewsbury is also worth a look - but you simply would not have time.https://www.visitshrewsbury.co.uk

A detour to the west would have taken you to Welshpool and Powis Castle - Which has lovely gardens:>http://www.nationaltrust.org.uk/powis-castle-and-garden

So, what I am pointing out is that many places of interest lie en-route - or near route. The chances are that you would not have much time to visit such places by doing this journey in 1 day. In fact, ideally, I would take 2 or even 3 days to do such a journey & having detoured to Welshpool to see Powis Castle, would then head west via Dolgellau & Barmouth to take in Harlech Castle on the west coast. So, consider the driving time plus visiting time. Doing it in 1 day means you have to simply keep driving for much of the time.

Check your timings / distances with the AA website. When going from Conwy to Keswick - I would call in at Chester.
http://www.visitchester.com
http://cadw.gov.wales/daysout/maps-and-itineraries/?lang=en
http://www.harlech.com
www.castlewales.com
http://www.visitwales.com
http://www.visitllandudno.org.uk
http://www.eryri-npa.gov.uk/home
http://www.snowdonrailway.co.uk
http://www.portmeirion-village.com
http://www.nationaltrust.org.uk/plas-newydd-country-house-and-gardens

James is right on. You can do Conwy in an hour so I would not linger. I would try to include Beaumaris if you have time.

Really, the whole castle in an hour? I have heard good things about it. Hmmm. I will have to look into James suggestions. Thanks!

I suppose I should also add that this is a trip with my sister who wants to see these particular ruined castles, as do I. My hubby and i are planning for a couple of years down the road to do a 2 week car trip of Wales on our own so I do not need to do everything on this trip. Just a few castles. Thanks!

Conwy Castle access is easy and you can walk the walls in an hour. The town of Conwy itself is small so you can easily move on to other sights such as Beaumaris which is only 24 miles away on the seacoast. We stay in B & Bs in the countryside when we travel. Just check with the Tourist Info Offices when you come into a town or at a train station.

I visited Caernarfon last summer and just fell in love with the castle. They have very good exhibits in the castle that tell you about the history of the castle. The coronation ceremony for the Prince of Wales is held here. We spent about 2 hours there just looking around and could have spent longer. I spent the night in Beaumaris but was unable to see the castle from the inside, only the outside due to time constraints. North Wales is a beautiful area.

My advice would be to check the opening hours of all the places you want to see and work out a route on the map.
I think your change of plan to do the walk around Conwy on the first night makes sense as it will take a full day to get from Bath to Conwy via Tinturn Abbey. If you arrive in time see it, if not, defer to day 3.
On day 2, I would visit Badnant Gardens when they open, then drive through Bewts-y-coed and Snowdonia Nationational Park to Caernarfon. On the drive back along the coast, you will get a great view of Beaumaris Castle. It is worth seeing but the view across the bay is as spectacular as the interior of the castle and I don't think that you will have the time to visit.
Before leaving Conwy on day 3, you could take a look at Conwy Castle.
Of all the castles, Caernarfon is the most impressive and historic.
Enjoy your trip.

I've done the drive between Conwy and Caernarfon through Betws-y-Coed. It is a narrow road with lots of tourist traffic. If your top three priorities are the castles and the gardens, I would skip Betws-y-Coed and Snowdonia National Park. For less driving and better roads, after you visit the gardens, drive back to Conwy and take the motorway to Caernarfon.

The previous poster is right about getting to Bodnant when it opens. These gardens are spectacular--almost as great as Sissinghurst and Hidcote, so you'll want to spend a good amount of time there. I also agree that Caernarfon has the most interesting castle, although Beaumaris is the most scenic.

Thanks for all the advice! We're going to do bath to Tintern Abbey, Ludlow Castle, then overnight in Conwy. Next day will do Carnarvon, then Bodnant and back to Conwy for sleeping. Will fit RS Conwy walk when we can, and Conwy Castle if possible, but not a must.

While in Conwy area Bodnant Gardens are a must. Caernarfon was IMHO more interesting than Beaumaris but if you are going to Anglesly and have time consider a country drive around the island, it is beautiful. Conwy castle closes early 4:30 I think so do it first. Conwy is a quiet town in the evening so there will be lots of time to walk the walls (always open)