Wikipedia
Cercanías is the name given to the commuter rail systems of Spain's major metropolitan areas. In the Valencian Community, the term is replaced by Rodalia , while the designation Aldiriak is used in the Basque Country. In Catalonia (where the main administrator is the regional government), it is commonly known as Rodalies .
Operated by the national rail company Renfe Operadora, Cercanías are in the process of being transferred to the regional autonomous governments. The former Rodalies Barcelona was handed over to the Catalan Government and renamed " Rodalies de Catalunya ".
There are currently twelve Cercanías systems in Spain (including the distinct Rodalies system in Catalonia): Asturias, Bilbao, Cádiz, Catalonia, Madrid, Málaga, Murcia/Alicante, Santander, San Sebastián, Seville, Valencia, and Zaragoza. It is well linked to Metro systems in Madrid, Barcelona, Bilbao and Valencia.
The Madrid Cercanîas network was the target of the 2004 Madrid train bombings. The attacks, which killed 191 people in Santa Eugenia, El Pozo and Atocha stations, were the bloodiest terrorist actions in Spain to date.