The M-30 tunnels are a set of four double-tube road tunnels, each of which are part of the M-30, Madrid's ring road. The total length of the four tunnels is 43,085 meters (43 kilometers). The M-30 tunnels form the largest network of urban tunnels in Europe.

Until 2004, the M-30, a ring road that circles the capital of Spain, ran on the surface through part of the city, especially in its eastern and southern sections. Mayor Alberto Ruiz-Gallardón was elected after the 2003 municipal elections and carried out the project consisting of burying the M-30 in its southern section, which coincides with the Manzanares River, and excavating a link between the M-30 south at the Toledo bridge and the M-30 east at its connection with the A-3 using a tunnel boring machine. In 2004, the works began, which lasted just over three years. Starting in January 2007, the tunnels were gradually opened.[1]​.