Aigle Castle is the reason to get off the train. Its towers and defensive walls sit just above the old town, surrounded by vineyards rather than the usual empty moat, with the Alps closing the view to the east.
Inside is the Vine, Wine and Wine Label Museum, a good fit for a region where the slopes are worked almost to the castle walls. Even if you skip the museum, the walk up through the vines and the view back across the Rhône valley make the detour worthwhile.