Visiting for 5 or 6 days to Buenos Aires.
If we decide we want to take a day trip- which would be better-Colonia or Areco?
Also, for Areco, if I do not ride horses, will I be bored? (hubby rides).Thanks.Forgot to mention, going in April.

Most of the estancia day trips near San Antonio de Areco offer a variety of things to do and see....watch gauchos on horseback do various tricks, singing and dancing, a BBQ dinner, tours of the grounds ( some estancias feature tours of the main house, others let you participate in typical farm activities such as milking a cow) and almost all of the estancias offer a ride in the back of a horse drawn cart or wagon in lieu of horseback riding....In short, no you will not be bored.

Which is best? It just depends on your interests. I have done both many times and my hands down favorite is an estancia visit.....

Is an estancia something you can arrange yourself or must you use a travel agency or have a hotel arrange it for you? Thanks.

You can arrange it yourself for some esctancias. Here are two:
http://www.estancialosdoshermanos.com/
http://www.donsilvano.com/english/index.php

Some others I think only book through agents or hotels...

Thanks again, Drdawggy for answering my question.

drdawggy and others-

Would it ever make sense to stay overnight in San Antonio de Areco in connection with a day trip to one of the local estancias?

I did both the Colonia trip and the estancia day on my recent trip to BA. I enjoyed both...I guess (knowing what I know now) I would choose Colonia if I could only do one, but it's a close call. They were both interesting in different ways. Colonia was so beautiful and peaceful...it was nice break from the noise and energy of BA.

I would not have wanted spend the night in San Antonio de Areco. It was awfully small...and the restaurants in BA are so freaking fantastic I would not have wanted to miss out on a single dinner in that city.

I went to Tigre-Delta region for the day. Took the train and then a boat trip, very nice. Alana