Brecon Beacons

The only time I spent in the Brecon Beacons was during my college days when we did an "outward bounds" week with the army, staying at the local barracks, sneaking out at night to visit the local pub (not one that I'd recommend) and getting up to all sorts of mischief. We did spend one day walking up Pen Y Fan, my first experience of climbing a mountain. I wouldn't describe it as mountain climbing, rather a strenuous hike. That was when I was 17 and the most exercise I undertook was the occasional game of football and a few rounds of pool in the pub.

The views were great from the summit so it's worth taking a look and see if it's something you'd consider. I can't offer any advice on food as we were subjected to military ration packs.

I just found seven mountain trains online in the Brecon Beacons area. When we were in Betws y coed we were told that a lot of people ride the trains up and then hike down. We loved this location on a cascading river with stone bridges. It is just south of Conwy. It is an adventure driving in Snowden over Horseshoe Pass...beware of sheep.

It looks like you would be about 30 minutes from Abergavenny. If you are over that way, perhaps to walk a section of the Three Castles Walk, there are two places I could suggest, one from recommendations (Michelin), and one from personal experience.

The first is the Walnut Tree, with a Michelin star.

https://www.thewalnuttreeinn.com

However, in the three nights we spent near there in a Band B, we did not make it there. We dined all three nights at the Hunters’ Moon Inn, a nice little pub with lovely hosts and great food.

https://www.hunters-moon-inn.co.uk/home

I think it's hard to go wrong with walks in the park. We had a lot of fun at the trail that was just off a five car/two picnic table pullout that promptly sent us to the gate to a cow pasture along with a stern sign about not bothering the livestock as we exercised our right to roam.

The Mynydd Illtud trail at the main visitors centre is another nice easy and sheep-filled walk with a good view once you get up the hill. The visitor's centre also has a nice craft shop staffed by local artisans (Margie made the earrings I bought there) and pretty tasty food in the tea room.

Check out:>http://www.breconbeacons.org

I see that your title says Breton Beacons instead of Brecon Beacons.

Now look at this map:>https://www.google.co.uk/maps/place/Llandeilo/@51.8876614,-4.0757197,12.14z/data=!4m5!3m4!1s0x486e5454b5330a4b:0xd59a1e8d7c74a1d8!8m2!3d51.88469!4d-3.99143!5m1!1e1

It shows the way you will be heading to the BB from St.David’s. You will be on the A40 to Carmarthen and can continue on that road all the way to Brecon going via Llandeilo and Llandovery. However, you may wish to take the A48 for a short distance E of Carmarthen and then visit the National Botanical Garden of Wales? If so, on leaving this place, follow the B4310 NW west to the Towy Valley & turn R onto the B4300. Soon you will see a sign for Dryslwyn Castle and it is well worth the short detour to see this ruin beside the Towy. (Climb to the top for fab views). Then return to B4300 & go E. https://botanicgarden.wales

Just SE of Llandeilo is CARREG CENNEN CASTLE - a ruin set on top of a very high cliff. https://cadw.gov.wales/daysout/Carreg-cennen-castle/?lang=en The farm at the base offers food in a barn. If you visit this castle, be sure to go down the passageway into the cave underneath. (The approach road to this castle is narrow). Now, you could go on backroads via Gwynfe and head NE into the Brecon Beacons National Park. However, I would not advise this for non Brits as the roads are VERY narrow and you will have to drive backwards to a passing place if you meet anyone. It is also easy to get lost. So, probably best to head back to Llandeilo and join the A40 for your journey towards Brecon via Llandovery. If you are heading towards Merthyr, take the A4215 from Sennybridge/Deffynog.

You don't say exactly where you are staying. Merthyr is an old industrial town and was one of the first places in the world to produce iron. It is not worth a visit but if you are into industrial stuff, you may wish to visit a coal mine (free) at Big Pit, Blaenavon.
https://museum.wales/bigpit/

Also consider:>http://www.showcaves.co.uk/prices_opening.html If going to the caves, you may also like to consider visiting some waterfalls. Scwd Gwadys is about a 30 minute walk from the Angle Inn at Pontneddfechan. Other waterfalls can be reached by following the road towards Ystradfellte and parking where you see a farm track going off to the east. The Upper Club Gwyn Fall is an easy 15 minute walk. Others are more strenuous and longer from roads - click & drag the following map NE and they will show up.
https://www.google.co.uk/maps/place/Pontneddfechan,+Neath+SA11+5NP/@51.7611544,-3.6034136,2493m/data=!3m1!1e3!4m5!3m4!1s0x486e4654455e3301:0xa0d8b265e0a8340!8m2!3d51.757066!4d-3.592109!5m1!1e1

The only narrow gauge steam railway in this area is found just N of Merthyr - be careful to follow signs as it is confusing:>
https://www.bmr.wales

JC I think strenuous is out and I know military rations are not in our plan. Funny what we did in our youth, though.

Kathleen I have looked at those trains and we may do one as my husband is a bit obsessed with trains, but the other couple not so much. It would be great to combine a train with a hike so I will delve into details.

Lola, thanks. Abergavenny is supposed to have a fine culinary rep and we are not staying too far away. That pub looks lovely!

Selkie I found that hike Mynydd Ilitud online and it appealed to me. Good to have a first hand recommendation.

James the website for Brecon Beacons is what gave me enough ideas for two weeks! Hoping to narrow the list with these great recommendations. We willl study your route recommendations and the castle looks worthy. We are actually in a holiday house close to Cyfarthfa Park Lake. Waterfalls are always a lovely possibility, too.

Spelling corrected in title, thanks. Darn autocorrect!

Hunters’ Moon is right on Offa’s Dyke Path, which traces the eastern border of Brecon Beacons National Park. You could put together a visit to Abergavenny markets, a nice ramble on the path, and an early dinner at the pub for a nice day out.

https://www.nationaltrail.co.uk/offas-dyke-path

When you are in north west Wales - The Welsh Highland Railway is well worth a trip:> https://www.festrail.co.uk/route.htm
Also consider:> https://portmeirion.wales

Presumably, you will going down the west coast between Aberystwyth and St.David’s? If so, Aberaeron is worth a look :> https://www.cardigan-bay.com/aberaeron-cardigan-bay.php

So, you are staying at Cyfartha. That being so, a much quicker route east from Carmarthen is the A48 to join the start of the M4. Leave the M4 at junction 43 near Neath and take the A465 expressway up the Vale of Neath. This entire route will be dual highway mostly with a speed limit of 70mph. It is only the final few miles from Hirwaun to Merthyr that are non dual and have lower limit. My previously mentioned northern route is non dual and much more winding. Using the fast southern route, it is still possible to visit the National Botanic Garden of Wales.

From Merthyr, it is only around a 35 minute drive to the northern edge of Cardiff via the A470 expressway. A short detour would take you to Caerphilly Castle. Castell Coch is not far away - see map link that follows. On it, you will see ‘Long Wood Nature Reserve’. If you were to drive to Longwood Drive towards the river and park for free, a short walk alongside the river (going south and then over the footbridge) - would bring you to Radyr station (marked with red arrow symbol). From here, trains run about every 10 minutes to the centre of Cardiff in around 11 minutes. I would suggest that you might like to take the train to the city centre where you will find Cardiff Castle. However, you may like to first visit Cardiff’s waterfront which would mean buying a through ticket to the Bay and involve a change of train at Queen Street. The return to Queen Street for the city centre/castle. That being so, ask for a return ticket from Radyr to Cardiff Bay. (This would probably not open the ticket barrier at Queen Street - so just show it to staff).
http://www.visitcardiff.com

If you don't fancy the centre of Cardiff/Bay, consider joining M4 at J32 & travel W for about 3 miles. Leave at J33 and take A4232 for just over 1 mile - turn left (sharp turn off slip road) into:>https://museum.wales/stfagans/castle-and-gardens/

Map of north Cardiff:>https://www.google.co.uk/maps/@51.5391325,-3.241005,8801m/data=!3m1!1e3!5m1!1e1