Behind the Casa Rosada, look for a glass wedge: it's the roof of this bright and airy museum, housed within the brick vaults of Argentina's old aduana (customs house). Head down into the open space, which has over a dozen side rooms, each dedicated to a different era of Argentina’s tumultuous political history. There are videos (in Spanish) and a few artifacts to see, along with an impressive restored mural by Mexican artist David Alfaro Siqueiros.