Puerto Madero is a waterfront district known for its high-rise buildings, luxurious hotels, and upscale restaurants. Once a neglected area, it underwent a massive regeneration effort in the 1990s, attracting local and foreign investment making it the youngest and most modern area of the city.
Personally, it isn't my favorite area of town as being so modern and polished it lacks the culture and grit that makes Buenos Aires what it is. I don't recommend dining here. Restaurants are pricier and many are chains or offering cheap happy hours for the local business crowd.
That said, if your feet are begging for a break, it IS a welcome quiet space for a beer or coffee by the water.
Don't miss the Puente de la Mujer. Often tango dancers perform here for tips.