On the West side of Parque Lezama, this is a beautiful building with fenced in grounds. I saw another review say it cost them a few bucks to get in, but it was free when we arrived on a Tuesday afternoon.
The staff was friendly and the tour guide we had was absolutely amazing and super knowledgeable. The museum is very well done, though it focuses on a narrower period of Argentine history, after European colonization through the civil war and ending with the liberation of Bolívar and his contemporaries.
There was a small section in the back focusing on Argentina's political history and celebrating 1984 when democracy finally ruled after a dark battle with dictators, military coups, and more. read more