The Spanish football federation will present four bids: Espanyol's Estadi Cornellà-El Prat, the new San Mamés in Bilbao, the new Mestalla in Valencia, and now that Madrid 2020 has failed, the would-have-been Olympic Stadium La Peineta in Madrid.
http://www.mundodeportivo.com/20130911/atletico-madrid/la-peineta-opta-a-ser-sede-del-euro-2020_54381310645.html
Estadi Cornellà-El Prat (40,500), near Barcelona, inaugurated in 2009.
New San Mamés Stadium in Bilbao (53,332), will host its inaugural La Liga match this coming Monday, though it's not completely finished. The remaining quarter of the stadium will be built on land that was occupied by the old San Mamés, which was demolished this summer. It will be completed in Spring 2015:
The Nou Mestalla in Valencia (75,100), construction began in 2007 and was expected to be inaugurated in 2009, but the works were postponed due to financial problems:
La Peineta in Madrid (70,000) won't have a running track now that it won't be hosting the Olympics. Atlético de Madrid is expected to move there by the 2016/17 season: