My husband and I are spending most of April in Lyon. I've perused lots of information online about day trips from there, but can you recommend your favorites and offer any special tips? We love scenic areas, interesting architecture, and food (of course!) and will be traveling by train. Thanks!

Dijon is a nice city, easily reachable by train and very walkable. Beaune is also quite nice and easy to reach by train.

Tournon and Tain l'Hermitage merit a long visit. There are the wine merchants to visit, particularly Chapoutier and the cooperative, scenic strolls on the riverbank or in the vineyards, and a little train excursion up into the limestone crags of the Ardèche. Top it off with dinner at Le Cérisier-- exquisite without breaking the bank.

I'm sure Pérouges and Vienne are already on your to do list. If design and industrial history attract you, have a look at St Etienne.

Vienne (with)all it's Roman stuff!).
Macon and Cluny,
Orange,
Geneva,
Chambery and Annecy,
Perouges...........
All depends on your interests