The ambitious plan by Madrid’s mayor Alberto Ruiz-Gallardón to submerge a section of the M30 ring motorway immediately adjacent to the old city centre within a tunnel was realised within a single term of office. The city undertook infrastructure measures over a total length of 43 kilometres, six of them along the banks of the River Manzanares, at a total cost of six billion Euro. West 8 together with a group of renowned architects from Madrid, united under the name MRIO arquitectos led by Ginés Garrido Colomero designed the master plan for Madrid RIO.