Second on La Plata.
About a 1 hr. collectivo ride from the station in Retiro.
Small, walkable city.
Great museums. I really like the Natural History museum- its like going back in time, especially the skeleton rooms.
Its in a very nice park, with gardens and follies and outdoor restaurants.
http://www.fcnym.unlp.edu.ar/museo/
Incredible photos, courtesy of Thomas Hobbs-
http://www.buenosairesphotographer.com/2008/09/natural-science-museum-in-la-plata.html
the Cathedral is well worth a visit, too.
The tour to the top of the tower is great.
Its an easy one day trip, leave mid morning, hop on a return bus either before or after dinner.
9 Museos within about a mile of each other.
http://maps.google.com/maps?hl=en&s...local_group&ct=image&resnum=1&ved=0CAQQtgMwAA
I think whether you like La Plata or not depends on you- I liked the architecture, which ranged from a lot of casa chorizos in a variety of styles, including art deco, up to brutalismo, which would be their public theater downtown.
I liked the sleepy, walkable quality, I loved Parque Bosque, I went to the automotive museum, which is actually pretty good,
http://www.coleccionrau.com.ar/index2.htm
I had a good asado outside in the parque, and in general I found it relaxing, pleasant, and very argentine in every way.
Good little art gallery there, too, which does artist residencies for foreign artists, so they have a show every couple months of an artist from abroad who has been living and working there-
http://www.residenciacorazon.com.ar/artists.htm
the cemetery is supposed to be pretty good, too, a mini version of Recoleta.