The Serre () is a

tributary A tributary, or an ''affluent'', is a stream or river that flows into a larger stream (''main stem'' or ''"parent"''), river, or a lake. A tributary does not flow directly into a sea or ocean. Tributaries, and the main stem river into which they ...

of the river

Oise Oise ( ; ; ) is a department in the north of France. It is named after the river Oise. Inhabitants of the department are called ''Oisiens'' () or ''Isariens'', after the Latin name for the river, Isara. It had a population of 829,419 in 2019.< ...

in northern

France France, officially the French Republic, is a country located primarily in Western Europe. Overseas France, Its overseas regions and territories include French Guiana in South America, Saint Pierre and Miquelon in the Atlantic Ocean#North Atlan ...

, in the departments of

Ardennes The Ardennes ( ; ; ; ; ), also known as the Ardennes Forest or Forest of Ardennes, is a region of extensive forests, rough terrain, rolling hills and ridges primarily in Belgium and Luxembourg, extending into Germany and France. Geological ...

and

Aisne Aisne ( , ; ; ) is a French departments of France, department in the Hauts-de-France region of northern France. It is named after the river Aisne (river), Aisne. In 2020, it had a population of 529,374. Geography The department borders No ...

. Its source is in the small village of La Férée, Ardennes, from which it flows west into the Aisne department. It flows through Montcornet, Marle and Crécy-sur-Serre and joins the Oise at

La Fère La Fère () is a commune in the Aisne department in Hauts-de-France in France. It was once famous for its military school (1720), one the oldest commissioned for instructing ordnance officers. History During World War II, Nazi Germany operat ...

. Its total length is .

References

Rivers of France Rivers of Hauts-de-France Rivers of Grand Est Rivers of Aisne Rivers of Ardennes (department) {{France-river-stub