The M-30 orbital motorway circles the central districts of Madrid, the capital city of Spain. It is the innermost ring road of the Spanish city, with a length of 32.5 km. Outer rings are named M-40, M-45 and M-50. Its length and the surface surrounded by the M-30 is comparable to the Boulevard Périphérique of Paris, the Grande Raccordo Anulare of Rome or the London Inner Ring Road.

Madrid is the capital and most populous city of Spain. The city has almost 3.4 million inhabitants and a metropolitan area population of approximately 7 million. It is the second-largest city in the European Union (EU), and its monocentric metropolitan area is the second-largest in the EU. The municipality covers 604.3 km2 (233.3 sq mi) geographical area. Madrid lies on the River Manzanares in the central part of the Iberian Peninsula at about 650 meters above mean sea level. The capital city of both Spain and the surrounding autonomous community of Madrid, it is also the political, economic, and cultural centre of the country. The climate of Madrid features hot summers and cool winters.