Map Extensions?

[Bannon]

I'm still new to Dom 2.

I've downloaded some maps from the Illwinter site. They do not appear in the window for map selection when I am starting a new game. I notice that some of my maps have different extensions in the file name (instead of .map). For example:

parganos.rar
chandrea.rar

Do you know if this is actually a map? If these are the maps -- should the extension be .map?

Thanks,
Bannon