So had a chance to think on this some more whilst rather bored painting a garden fence....thought it was better than risking bank holiday traffic!
Here's some ideas from walks we've done on holidays.
1. Swanage to Corfe Castle along the Purbeck Way then steam train back on the Swanage Railway- about 6 miles
2. On the Swanage holiday again we got the ferry from Studland to Sandbanks then another ferry to Brownsea Island. It was October half term so the red squirrels were very active, great to see them, there is also lots of bird life including water birds on the lagoon. The island is only 1mile long by 1 mile wide so really easy to walk around. If you are in to wildlife it's a great place to spend a day. NT tea room too.
3. Lake District get the Ullswater Steamer to Howtown then walk to Glenridding along the lake shore. Wainwright described it as one of the nicest paths in Lakeland and who am I to argue! A tea room has opened in a barn about half a mile after Sandwick which was a pleasant surprise the first time I did this walk last year
http://www.becksidefarm.co.uk/cafe/ I enjoyed the walk so much did it again this year on a day when it was blowing a gale up high.
4 You can do something similar on Derwent Water.We got ferry from Keswick went a couple of stops. Got off and walked a chunk of lakeshore path then got the ferry again back to where we started. No café though!
5. Years ago, pre kids, hubby and I walked from Eskdale Green to Ravenglass over Muncaster Fell. Its a low fell only 231m at it's highest. Distance is about 6 miles . You then return back to the start on the narrow gauge Ravenglass and Eskdale Railway. Can't remember what we did for refreshments though!
6. Gower- Parkmill to Three Cliffs Bay then round the coast path to Oxwich bus back. About five miles. Ice creams etc available at both start and finish. Beautiful coast path walking, if the tide is out you can walk pretty much all the way along the beach. On a good day you can get there in less than 2 hours so do-able as a day trip from Bris.
7. Again not too far away the Severn Valley Railway could offer opportunities for walks along the river and steam trains. We have been on the railway but the kids were really little so didn't combine it with a walk.
8.One last localish one Symmonds Yat has the hand ferry, link it with a walk to the suspension bridge at Biblins or up into the forest. I had a nice day doing this earlier this year. Pubs by the river and a café up at the viewpoint.