BBC Sport assesses the strengths and weaknesses of Madrid's bid to stage the Olympics in 2012.
Madrid has promised to host a 'green' Olympics if it is given the Games in 2012.
THE MADRID BID
Airport 12 mins from city centre and key Olympic zones
Three venue zones within a 10km radius
Car-free, environmentally friendly Games
Olympic transport lanes
70% of facilities already built
The Spanish city is one of the few major European capitals yet to have hosted the Games and mayor Alberto Ruiz-Gallardon said: "Respect for the environment governs all aspects of this project.
"Madrid will use the opportunity of this candidacy to introduce renewable energies in all installations and hydrogen in public transport and could celebrate the first games without private transport."
Madrid's only previous attempt at a bid was in 1972, when Munich won, and the recent staging of the Olympics in Barcelona in 1992 could be a mixed blessing.
Barcelona's success boosted Spain's reputation on the sporting stage.
But the timing makes it less likely that the event would return there just 20 years on.
The Madrid bid ranked second in the International Olympic Committee's evaluation of the candidate cities last May.
But it has been replaced by London as the main challenger to favourite Paris after receiving a solid, but unspectacular assessment from IOC inspectors on 6 June.
Madrid's plan revolves around three main venue zones, close to each other and to the city centre.
Olympic history: 1992 (Barcelona)
Other Spanish bids: 2008 (Seville), 1972 (Madrid)
Betting odds: 10-1
The eastern sector will house the Olympic stadium - a renovated version of the current athletics stadium - the aquatic centre, velodrome, media and press centres and a number of other venues.
The bid has enlisted Real Madrid star Raul as an ambassador, and Real's famous Santiago Bernabeu stadium is inked in as one of the central venues.
Equestrian events, modern pentathlon, archery, mountain biking, triathlon and basketball would be staged in the west.
Outside the city, rowing and canoeing will be 47km away at Aranjuez, sailing in Majorca and football preliminaries in Alicante, Barcelona, Cordoba and Malaga.
The city says 70% of the infrastructure it needs to host the Games is already in place, and its transport network was praised by the IOC inspectors.