Seine-Saint-Denis is a department of France located in the
Île-de-France region and part of the Grand Paris area. It is well-known for its official administrative number, which is 93 and is often referred to as "quatre-vingt treize" or "neuf trois". Seine-Saint-Denis and two other small departments, Hauts-de-Seine and Val-de-Marne, form a ring around Paris called the "Petite Couronne", a highly populated area. Since January 1, 2016, it has been officially incorporated into the Greater Paris area, an important administrative region of France. The department is composed of 40 communes with a population of over 1.5 million. Saint-Denis is the most populated commune in Seine-Saint-Denis, home to many historical landmarks and cultural attractions. The prefecture of Seine-Saint-Denis is Bobigny, which is the eleventh-most populous commune in the department.