Barajas International airport by jacob_m
The international airport is called Barajas and is located NE of the city. To go to the city center there are three opportunities. The bus is quick and cheap and the busstop in town is at Plaza de Colon, remember that during rushhour the journey takes much longer so have some extra time for the bus.The taxis in Madrid are about the cheapest in Europe and the trip from the airport shouldn't be expensive at all but be aware of the trafic during rushhour.
There is now also a Metro station at the airport but to get to the city center you have to change at least once (normally twice) so in my opinion it's not really a good alternative if you're in a hurry or have heavy luggage.
