Train Travel in Cornwall

Thank you kernow1300.

"P.O.S.H."

Very clever David. Thank you.

You are more likely to have the sun in your eyes if sitting on the south side of the train. Trains in Britain drive on the left - so trains going the other way pass on the right side. Between London & Reading are 4 tracks so sit on the right westbound of you want to see the passing trains on the other 3 tracks. The best views are on the south side especially between Exeter and Newton Abbot where the railway hugs the coast. Some coaches don't have reserved seats and you can sit in any vacant seat. Some seats have better window alignment than others and I always prefer to be forward facing.

Be sure to sit on the left side of the carriage, at the very least, from Exeter St. David's to Newton Abbot, when the train goes right along the sea

Thanks James and Samuel. I am going to take the liberty of pushing us a little further. From Falmouth to Bristol, any further recommendations?

When in Penzance, I would suggest that you take the short train ride to St.Ives. To do that, you need to change at St.Erth from the mainline to the St.Ives branch line. Buy on the day a return ticket for about £5.
https://www.visitcornwall.com
http://www.railrover.org/pages/cornwall-ranger.html

When in Falmouth, try & list Trebah Garden and maybe Glendurgan. https://www.trebahgarden.co.uk
https://www.nationaltrust.org.uk/visit/cornwall/glendurgan-garden

If you are into trains, you might like to take a ride on >https://www.southdevonrailway.co.uk
To do this, you would travel to Totnes (on the mainline) to transfer to the heritage steam railway. Totnes is also an attractive town to look around or stay a night or 2. Ferries also go from Totnes down the estuary to Dartmouth. In fact, you can buy a special ticket that includes the ferry plus another steam train from Dartmouth / Kingswear to Paignton and your journey back to Totnes. (Your trains to/from Cornwall will stop at Totnes).

2 railways go from Exeter to London with the fastest being the GWR to Paddington. The other one is South Western Railway which goes to London Waterloo. This route uses diesel multiple units with underfloor engines.

It is perfectly viable to travel back from the south west via Bristol (Temple Meads is the main station). But, I would suggest you go to Bristol and change for the short hop to Bath and stay a night or 2 before heading back to London. That will give you a different line between Taunton & Reading compared to the one you travelled out on.
Video - London to Bath by Train.https://www.youtube.com/watch?v=xpp6vAs2W4I

You may like to get a 2 *Together Railcard for £30 as this will reduce fares by a third. You will find the cheapest prices for the longer journeys by pre-booking Advance tickets (not refundable) for specific trains around 11 weeks out. Also note that it is sometimes cheaper to split the ticket. These 2 sites will tell you if splitting is cheaper. On trainsplit - click ‘Proceed’ and it will tell you the splits and prices for each leg. As a guide, you should be able to get from Penzance to Bath for £32.61 departing at 9.25 (non Railcard price) tested today for Tues 7 February. * Not valid weekdays before 9.30am.
https://v3.trainsplit.com
https://www.traintickets.com/?/