I highly recommend visiting Plaza de Mayo on a Thursday afternoon to see the Madres speak about their missing children in front of the Casa Rosada. Here at their headquarters, on Plaza Congreso, you can learn even more. This complex contains the office of the Madres, the Universidad Popular Madres de Plaza de Mayo, the Librería de las Madres, the Café Literario Osvaldo Bayer, and the Biblioteca Popular Julio Huasi, among other facilities. At this busy center of activity, you will find the Madres themselves, now mostly very old women, surrounded by young people who come to work and take university classes with a decidedly leftist bent. Many lectures, video conferences, and art exhibitions are held throughout the space. The bookstore has perhaps the largest collection of books anywhere in the world on Che Guevara, a Madres personal hero, though he was killed before their movement began. The large library of reference books on liberal causes is decorated with depictions of events around the world in which people have sought justice from their governments. On Friday, Saturday, and Sunday from 11am to 6pm, the Madres hold a fundraising market with antiques, crafts, food, book vendors, and occasional live music on Plaza Congreso, in front of the building. This is also good for children, because it is next to the part of the park with the merry-go-round and other rides.