Top of the list must be the Vale of Rheidol Railway. The first bit of the run out of Aberystwyth is flat and uninspiring but once you begin to climb up the valley it is a magnificent run.
Devils Bridge can be accessed off the railway but you may not have time to do the walks if you are on the train. It is well worth driving up and spending as long as you want here as the walks are superb. You will want your camera. Full information and map on the web site.
Quite close to Devil's Bridge is The Arches Car Park where there are 5 easy walks. You could easily spend half a day around here.
There is a nice coastal walk between Borth and Aberystwyth
Have a look at this website which has lots of ideas for walks on Forestry Commission land around Aberystwyth
For something completely different there is Llywernog Lead Silver Mine.
Thanks EESW that is just the type of advice I am looking for and I will investigate those links
A few more thoughts:
Strata Florida Abbey is a few miles south of Devil's Bridge. The kids might enjoy exploring here.
A bit further to drive are the Roman Gold Mines at Dolaucothi. You can try your hand at panning for gold and there is an underground tour.
Aberaeron is a pretty little village down the coast from Aberystwyth. You might be interested in visiting
Llanerchaeron, an 18thC estate of the Welsh gentry which has been lovingly restored by the National Trust. I've not visited here - it is 'on the list' but we've not made it yet!
All above suggestions are good. Not far from the Arch car park is HAFOD. I can especially recommend the walks here, park by the church near Cwmystwyth; there's an information board etc there. Have a look here
http://www.hafod.org For the background story read "Peacocks in Paradise" by Elizabeth Inglis-Jones; a truly captivating story. You could then visit the Elan Valley lakes via the mountain road to Rhayader.
A little further afield is Llanidloes with the Hafren Forest and Clywedog reservoir. see http://www.llanidloes.com. The drive back to Machynlleth (and Borth) over the Clywedog plateau via Dylife is just about the most spectacular drive in Wales (pick a clear day!!)
There is a train station in Borth with trains every 2 hours into Aberystwyth, or north towards Machynlleth, where you can change trains to go up to Barmouth & Pwllheli.Ideal if you wanted to have a rest from driving, & be able to view the scenery. The ride up to Pwllheli is lovely with sea views. Go to thecambrianline.co.uk for more information. You can download a leaflet the cambrian coast gazer, which tells you what you can see.
North of Machynlleth on the A487 is the Corris craft centre, & King Arthurs labyrinth ( underground caverns ) See kingarthurslabyrinth.co.uk for more info on both of these. There is a nice cafe here too. After this come out onto main road turn left, continue on this road then take the next left B4405 to Tywyn, this will take you past Tal-y-llyn lake, & follow the route of the Tal-y-llyn railway, some of the stations can be accessed from this road. At the next junction turn left towards Tywyn, along here on the left there is a factory which makes honey ice cream, there is a shop where you can try the flavour of the day. In Tywyn itself there is the main staion for the railway. After passing Tywyn head on the A493 to Aberdovey, this road then takes you along the estuary towards Machynlleth. If you get a taste for the ice cream & you are in Aberaeron there is a shop selling it on the harbour , there is always a queue it is so good, there is an excellent fish & chip shop there too, & you can eat inside (the portions are huge). Nearer to Borth, at the northern end of Bow Street, is Pennau crafts & cafe, lovely homemade food, ideal for lunchtime stop. In Borth itself there are 3 pubs that are family friendly & serve food, also there are several small cafes.
Finally the red kite feeding at Bwch Nant Yr Arian, takes place at 3pm every day. See nantyrarian.com
Oh, I almost forgot our 3 miles of beach. If you want any further info please ask, I actually live in Borth, hope the sun shines for you.
Also the Rheidol valley with the hydro power station and the trout farm - head south off the A44 in Capel Bangor.
A favorite evening outing when I was younger was to buy an evening rover ticket on the train - still available see thecambrianline.co.uk/cambriancoasterrover.h… - you can get on the train in Borth and with some train changes roam up the coast getting off where you want then returning late in the evening, very scenic.Edited: 1:23 am, June 12, 2010
Edinacloud also maybe think. Exploring the rock pools at low tide and walking around the headland, understanding what you are seeing with the petrified forest on the beach, exploring the dunes in Ynyslas, trout fishing in the Leri - even if the sky is a scary mass of gray you really don't need to go far from Borth!
I joke with my relatives (my mother lives in Borth though I frequent further shores most of the time) that while being a confirmed atheist there is mystical quality to Borth - if it decides to adopt you it won't let you go and you are destined to return, it hasn't finished with me yet. Beware lol.
Enjoy your trip TOFFEESKIP.Edited: 1:41 am, June 12, 2010
Arggh I hate the new spelling correction and the limited edit . Edinacloud "made me think" not "maybe think" lol