I opted for the free tour of the French Embassy instead of the pricey brunch today. It was a three-hour wait for the guided tour of the palace that was recently renovated. They were considering tearing it down in the 1970s to expand Nueve de Julio, but it was saved at the last hour. The palace is spectacular. After 15 years in BA, I finally made a point to see it with a Parisian friend who lives here.
You'll have to wait a year until the next open house.