The Alas Building is a Rationalist residential and office building in the San Nicolás section of Buenos Aires, Argentina. It is 141 metres (463 ft) high with 41 floors. Alas was the tallest building in Buenos Aires between 1955 and 1995, when it was surpassed by the Le Parc tower. It has long been part of the skyline of Buenos Aires. As of 2009, it was the 20th tallest building in Argentina.