Seine-Saint-Denis is a French department located in the Île-de-France region. Locally, it is often referred to colloquially as quatre-vingt treize or neuf trois, after its official administrative number, 93.
The learned and rarely used demonym for the inhabitants is Séquano-Dionysiens; more common is Dionysiens.
Wikipedia https://en.wikipedia.org/wiki/Seine-Saint-Denis
Coordinates 48°54'22.993" N 2°26'42.803" E