Bus services in the Yonne are inexpensive (€2 per ride) but extremely limited. TransYonne runs regularly scheduled buses no more than once or twice a day; additional services are available on demand, but you must reserve the day before, prior to 5pm, by internet or phone. Get timetables online or at local tourist offices.
Line 2 Links Auxerre with Pontigny.
Line 4 Links Auxerre with Chablis and Tonnerre.
Line 5 Links Avallon with Noyers-sur-Serein and Tonnerre.
Line 6 Links Auxerre with Avallon.