We assume that most attendees will arrive to Madrid by the "Adolfo Suárez - Madrid - Barajas - International Airport" that is served by many airlines (including low-cost ones). The official airport website is here, where you can find a list of the airlines currently serving the airport and destinations worldwide with direct flights.
The airport is directly linked to the metropolitan public transportation network both by "metro" (all terminals) or by suburban rail "cercanías" (only Terminal 4) In addition, there exists a flat rate (currently 30 €) for taxis from the airport to downtown Madrid (including the Conference Venue)
In addition. Madrid is well linked by high speed train, particularly (via Barcelona) with southeastern France. It may be a sensible option for attendees coming from Toulouse, Marseille, and even Lyon
If anybody needs further directions to get to Madrid by any means, please, don't hesitate to contact the organization at imt12@ucm.es
Sightseeing in Madrid
The official tourism website of Madrid-City is here
The official tourism website of Madrid-Region is here