While some might argue that not all of the food in Sri Lanka is that great, one of the most overlooked delicacies of this country is the travel snacks. Walk near any bus or train station and you'll find a bevy of vendors selling salty snacks and juicy fruit.
The range of salty snacks is very immense. From a variety of deep fried roots, extruded snacks, to a large variety of spiced nuts, these snack shops have something for everybody. The only thing you'll have to be careful about is the spicy factor. If you're very sensitive to spicy food you may get burnt, literally. Even the non-spicy snacks have a little kick to them. You may also notice that there are some strange black or green bits and pieces in your snacks, they are supposed to be there. In some cases the spices used in these snacks are not ground to a powder, and instead are left in their full size. This actually enhances the flavour of the spice and adds to the texture.
The other vendors you'll see around these bus and train stations are fruit vendors. Since this is a fairly warm and wet island, fruit is abundant. Many of the trees you'll see on your train or bus ride probably produce the fruit you're eating. The fruit is very fresh, and if you're going on the train the vendor will often prepare it for you for easy traveling. Some vendors even have pre-made travel ready bags of fruit ready to go.