Even though Buenos Aires takes the lion's share of postmarks found on air mail covers from Argentina to other countries, some covers are postmarked from cities and towns outside Buenos Aires, including those that are not provincial capitals. Here are two examples. The cover shown below, addressed to Boston, U.S., is postmarked "EL PALOMAR 75." I show a detail of the postmark.

Below is a cover to Machodoo, V.A., U.S. postmarked by a neat "CASTELAR 86."