When visiting Puerto Madero you MUST take a tour and see a well preserved piece of naval history. The entrance is 3 pesos (less than a bottle of water) but the joy is bigger, especially if you travel with kids.
Great place for taking pictures and another spot for admiring Puerto Madero.

The ship in the spictures is the Fragata ARA Sarmiento, now a museum, The actual training vessel, the Fragata ARA LIbertada is further up North in the port and is an active sail training ship

For forty years the Fragata ARA Presidente Sarmiento served as a training vessel for the Argentinian Navy. Today it sits, having been transformed into a museum, anchored in the canal in Puerto Madero. For only 2 Pesos ($.50 USD), you can gain entry to the ship and can explore many areas that in the US would be closed due to safety and accessibility reasons. Argentina did an excellent job converting the vessel including the addition of images, displays, documents and explanations (in Spanish only) of what you are actually exploring. Truthfully, they could charge ten times what they do and it would be worth visiting. The ship itself is gorgeous, full of highly polished wood and brass contrasted with freshly painted black and white metal. You certainly learn a great deal about the time it spent on sea, and just how it managed to sail across the world 37 times all while freely exploring nearly five stories of history.

If you are around Puerto Madero, take a few minutes to visit the Fragata.

I'm sure you'll enjoy the time going up and down the vessel and learn a bit more about how the life in the Ocean must look like.