.ar is a national top-level domain for Argentina. It's administrated by "NIC Argentina".
Secondl-level domains Edit
.com.ar (for public access)
.edu.ar (for educational establishments)
.gob.ar (for state establishments (also can be used .gov.ar))
.int.ar (for international organisations)
.mil.ar (for military establishments)
.net.ar (for local internet service providers)
.org.ar (for nonprofit organisations)
.tur.ar (for official touristical travel agencies)
P.S. The .gob.ar was approved in 2008. (gob. is a reduction of a Spanish word "gobierno", which is translated as "government"). Also in this year in the domains were approved special Spanish symbols: ñ, á, é, í, ó, ú, ä, ë, ï, ö, and ü.