The Seuil de Naurouze, aka Col de Naurouze, is a mountain pass in southern France. It is the watershed point identified by Pierre-Paul Riquet

Pierre-Paul Riquet

Pierre-Paul Riquet was the engineer and canal-builder responsible for the construction of the Canal du Midi.-Background:...

 when he designed and built the Canal du Midi

Canal du Midi

The is a long canal in Southern France . The canal connects the Garonne River to the on the Mediterranean and along with the Canal de Garonne forms the Canal des Deux Mers joining the Atlantic to the Mediterranean. The canal runs from the city of Toulouse down to the Étang de Thau...

. Water falling on the western side of this point flows to the Atlantic Ocean

Atlantic Ocean

The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...

 and on the eastern side to the Mediterranean Sea

Mediterranean Sea

The Mediterranean Sea is a sea connected to the Atlantic Ocean surrounded by the Mediterranean region and almost completely enclosed by land: on the north by Anatolia and Europe, on the south by North Africa, and on the east by the Levant...

. It is on the border of the department of Haute-Garonne

Haute-Garonne

Haute-Garonne is a department in the southwest of France named after the Garonne river. Its main city is Toulouse.-History:Haute-Garonne is one of the original 83 departments created during the French Revolution on March 4, 1790. It was created from part of the former province of Languedoc.The...

 and the department of the Aude

Aude

Aude is a department in south-central France named after the river Aude. The local council also calls the department "Cathar Country".Aude is also a frequent feminine French given name in Francophone countries, deriving initially from Aude or Oda, a wife of Bertrand, Duke of Aquitaine, and mother...

.
In 1827, the heirs of Riquet

Pierre-Paul Riquet

Pierre-Paul Riquet was the engineer and canal-builder responsible for the construction of the Canal du Midi.-Background:...

 built the Riquet Obelisk

Riquet Obelisk

The Riquet Obelisk is dedicated to the creater of the Canal du Midi, Pierre-Paul Riquet. In 1827, the heirs of Riquet built the monument. The obelisk has a dedication: "To Pierre-Paul Riquet, Baron Bonrepos, author of the Two Seas Canal in Languedoc"...

. The obelisk

Obelisk

An obelisk is a tall, four-sided, narrow tapering monument which ends in a pyramid-like shape at the top, and is said to resemble a petrified ray of the sun-disk. A pair of obelisks usually stood in front of a pylon...

 has a dedication: "To Pierre-Paul Riquet, Baron Bonrepos, author of the Two Seas Canal in Languedoc". It is erected near the site of the former octagonal holding tank, called the Bassin de Naurouze

Bassin de Naurouze

The Bassin de Naurouze is an octagonal holding tank, created during the building of the Canal du Midi as designed and built by Pierre-Paul Riquet. It was abandoned a few years after construction of the canal because of its recurrent silting problems. The flow of water from the...

 created during the building of the Canal du Midi

Canal du Midi

The is a long canal in Southern France . The canal connects the Garonne River to the on the Mediterranean and along with the Canal de Garonne forms the Canal des Deux Mers joining the Atlantic to the Mediterranean. The canal runs from the city of Toulouse down to the Étang de Thau...

.

The flow of water from the Bassin de St. Ferr%C3%A9ol joins the Canal du Midi

Canal du Midi

The is a long canal in Southern France . The canal connects the Garonne River to the on the Mediterranean and along with the Canal de Garonne forms the Canal des Deux Mers joining the Atlantic to the Mediterranean. The canal runs from the city of Toulouse down to the Étang de Thau...

at this point.