Coordinates: 50°27′10″N 2°32′17″E / 50.4528°N 2.5381°E / 50.4528; 2.5381

Houdain is a commune in the Pas-de-Calais department in the Nord-Pas-de-Calais region of France.

A former coalmining, now a light industrial and farming town, situated some 3 miles (4.8 km) south of Béthune at the junction of the D86, D301 and the D341 roads. The small rivers Lawe and Blanche join within the commune.

Coordinates: 50°17′53″N 3°47′56″E / 50.2981°N 3.7989°E / 50.2981; 3.7989

Bavay is a commune in the Nord department in northern France.

It lies 15 m. ESE of Valenciennes by railway.

Under the name of Bagacum or Bavacum, the town was the capital of the Nervii and, under the Roman Empire, an important center of roads, the meeting-place of which was marked by a milestone, destroyed in the 17th century and replaced in the 19th century by a column. Bavay was destroyed during the barbarian invasions and never recovered its old importance. It suffered much during the wars of the 15th, 16th and 17th centuries. One of the Roman highways connected Bavay to Tongeren via the relay of Liberchies, and later on continued to Cologne.

The town carries on the manufacture of iron goods and of fertilizers.