The source of the Yonne is on the Prénely mountain on the southern end of the Morvan hills in the Glux-en-Glenne commune, Nièvre department, at an altitude of about 738 m (2,421 ft).

The Yonne flows, in general, from the southeast to the northwest and passes through the 115 communes, most of them in the Bourgogne-Franche-Comté region; the main communes are:
Nièvre (58): Corbigny, Clamecy
Yonne (89): Auxerre, Joigny, Sens, Pont-sur-Yonne, Villeneuve-sur-Yonne
Seine-et-Marne (77): Montereau-Fault-Yonne
Finally, it flows, as a left tributary, into the Seine river in the town of Montereau-Fault-Yonne, at 47 m (154 ft) of altitude.
The source of the Yonne is on the Prénely mountain on the southern end of the Morvan hills in the Glux-en-Glenne commune, Nièvre department, at an altitude of about 738 m (2,421 ft).
The Yonne flows, in general, from the southeast to the northwest and passes through the 115 communes, most of them in the Bourgogne-Franche-Comté region; the main communes are:
Nièvre (58): Corbigny, Clamecy
Yonne (89): Auxerre, Joigny, Sens, Pont-sur-Yonne, Villeneuve-sur-Yonne
Seine-et-Marne (77): Montereau-Fault-Yonne
Finally, it flows, as a left tributary, into the Seine river in the town of Montereau-Fault-Yonne, at 47 m (154 ft) of altitude.
Yonne (river)