Have a read up about 'Hen Bermo' Hugo, then walk up through the houses to Ruskin's Cottages which are built almost on top of each other. Fascinating history and marvellous views.
The walk will be nothing to you fit fellows, but just about kills me it is so steep !
If you can obtain a book called " Discover Barmouth today and yesterday" by Owena Wyn - Jones and John Jones, it makes a good and informative read. Only one shop in the town stocks it and that is on the main street opposite one with Strawberries in it's name.......unless you can pick one up on the internet. The big church was 1/2 built and the tower collapsed in 1891, the bridge almost collapsed after being infested with shipworm, the museum to do with the Bronze Bell is interesting. Sorry, but I can bore for Britain on various subjects !