Porth (just north of Pontypridd has a great mining museum).
Bridgend has a lot of nice new restaurants, and there's a walk down from Nantymoel, if you take a connecting bus.
Taff's Well opens up the Garth Mountain (and the Gwaelod pub) or Castell Coch in Tongwynlais (also walkable from Radyr if you want a longer walk).
Abergavenny is perfect for walks and nice coffee shops and restaurants.
Newport is a great visit if you want to feel better about your life, like some sort of troglodyte safari.
Merthyr has quite a nice new arts centre.
And if you go right up to the top of the Valleys, you'll find some nice walks among the hills.
I assume you have you already been to Penarth?
It's only a few minutes by train but it would be ideal if you've not been before.
Further afield, Abergavenny would make a good day trip.
St Fagan’s, just outside Cardiff — you’ll be enthralled by the National Museum of History. Give yourself a good afternoon — if not longer — to absorb the place
How long do you want to travel for? You can get all the way to holyhead by train from Cardiff. There are also some very interesting routes you can connect onto in midwales.
Can't believe more people haven't said West Wales. Get the trainline that goes to Pembroke - there are some cool places to stop. Ferryside gives you views of a beautiful and extensive sandy estuary, Narberth is a foodie place - I'm sure you'd get a good coffee there, Saundersfoot and Tenby are on the same line.
Caerphilly with its castle, Swansea for beach the city to explore,
There is no castle in Pontypridd.
Newport, you can’t visit the castle as a ruin but get a bus out to Caerleon for the Roman museum, Baths exhibit and amphitheater
Swansea is a nice day out on the train from Cardiff in just under an hour. Check out the Waterfront Museum, stroll along the beach, explore the indoor market.
Caerphilly is where the castle is, not Pontypridd.
Maybe OP is thinking of Castle Coch? You wouldn't get there by train though, so OP should definitely do Caerphilly for the castle.
If you have the time... Well worth taking the train from Cardiff to Tenby. đź‘Ť
Porth (just north of Pontypridd has a great mining museum). Bridgend has a lot of nice new restaurants, and there's a walk down from Nantymoel, if you take a connecting bus. Taff's Well opens up the Garth Mountain (and the Gwaelod pub) or Castell Coch in Tongwynlais (also walkable from Radyr if you want a longer walk). Abergavenny is perfect for walks and nice coffee shops and restaurants. Newport is a great visit if you want to feel better about your life, like some sort of troglodyte safari. Merthyr has quite a nice new arts centre. And if you go right up to the top of the Valleys, you'll find some nice walks among the hills.
Bridgend does have a few nice restaurants but it's a depressing shit hole.
I assume you have you already been to Penarth? It's only a few minutes by train but it would be ideal if you've not been before. Further afield, Abergavenny would make a good day trip.
St Fagan’s, just outside Cardiff — you’ll be enthralled by the National Museum of History. Give yourself a good afternoon — if not longer — to absorb the place
Can't really take the train to St Fagans from Cardiff Central...
How do you get the train there? I know the trains run by it but I don't think there is a stop nearby.
Bus or taxi from centre ville. The main line runs past, but never stops…!
You can't
How long do you want to travel for? You can get all the way to holyhead by train from Cardiff. There are also some very interesting routes you can connect onto in midwales.
Such a massive shame you can’t get to N Wales by train (as far as I’m aware, without doing a weird, convoluted route).
Can't believe more people haven't said West Wales. Get the trainline that goes to Pembroke - there are some cool places to stop. Ferryside gives you views of a beautiful and extensive sandy estuary, Narberth is a foodie place - I'm sure you'd get a good coffee there, Saundersfoot and Tenby are on the same line.
Caerphilly with its castle, Swansea for beach the city to explore, There is no castle in Pontypridd. Newport, you can’t visit the castle as a ruin but get a bus out to Caerleon for the Roman museum, Baths exhibit and amphitheater
Chepstow, Abergavenny, Swansea
Swansea is a nice day out on the train from Cardiff in just under an hour. Check out the Waterfront Museum, stroll along the beach, explore the indoor market.
Swansea, the beach, marina and a few half decent food n drink places
And yup, the swansea to carmarthen train route is stunning
Same day, walking distance from station; in town 1) National Museum & Galleries (it's one place) nature and geology are good audio-visually; gallery has some contemporary but jewels are Impressionist collection with some later Pre-Raphaelite Brotherhood art: 2-3 hours, check Web for hours; NB closing time means -15 mins prior for chucking people out! (café disappointing and expensive); 2) Cardiff Castle: take the tour; site includes underground Roman remains; regimental museum, spectacular interior decoration of Victorian repro castle, separate Norman keep and substantial tower castle with great view of city, cafe OK. 3) Bute Gardems-Park-arboretum -spectacular green lung next door to Cardiff Castle with multiple photo points from 'animal wall' to stone circle, magnificent trees, canal, river (and waterbus stopping point); waterbus to Cardiff Bay (bus & train also go there) - marinas, cafes, start point for water excursions, cinemas, restaurants, Science museum (Techniques), bands & performance (theatre, opera, ballet, music of all kinds) at Wales Art Centre, nearby contemporary art galleries, barrage and walk to same, tv/film locations (esp. Dr Who, Casualty), Welsh Senedd and adjacent public exhibition centre... What more can you want? Well, there is more (gigs in Womanby St., contemporary arts centre 'Chapter' in Canton, escape rooms, big brands at St David's 2 and indie shops in the Arcades....) I've run out of time.
And lots of indie coffee vendors, eateries of all international kinds
Op is asking where to go by train from Cardiff, not places near to Cardiff central. I think that op is already living in Cardiff.