There are free guided tours at the Casa Rosada, the presidential palace of Argentina in the historic heart of Buenos Aires. During the tour you get the chance of posing with the palace guards for a picture. I love this part because it is fun for everybody and you can even see the guards slightly smiling. I'm not sure if these guards are the elite military force of Argentina or not, but I guess so. I'm just wondering. Thus it would be great if someone could enlighten me. Anyway, I'd really recommend the tour because you can see a lot.