Breil-sur-Roya is a lovely old town with a river running through it, overlooked by vast mountains and surrounded by terraced olive groves.
The streets are so narrow that it can be difficult to step back and take a good look at the buildings; to gain a little perspective, scramble up to the ruins of the old castle behind the town. You'll find a little path called Montée du Caste leading up from the town, and then it's a short scramble through an overgrown path to a tatty excuse for a flag at the top. All that remains of the castle is a few stones and half-buried walls but the views are excellent and its a nice place to take a picnic.
If you have 1 ½ hours to spare and a decent pair of shoes you can hike up to the Tour Cruella, a 13th century fortified tower that looks over the town. It is named after a bird of prey and has nothing to do with Dalmatian puppies.
Rue Pasteur is the main street that runs through the centre of the village; a narrow pedestrian passageway lined with small shops where you can buy fresh bread, meat, cheeses and other local goods. Small alleyways link it to parallel streets where tall narrow houses almost seem to lean in over your head.
The river that runs through Breil-sur-Roya widens out when it passes the town and a hydro-electric dam at one end forms a lovely little lake where you'll often see locals fishing for trout.