Tucuman actually has some great Art Deco Architecture, and if you are interested in railways, the Tafi Viejo musuem and rail repair yards are worth a visit.
Plus, it is rumored that the great, lost art deco streamlined locomotive, "Argentina", is languishing in a shed in Tucuman- that would be enough bait for me, any day of the year.
http://www.martynbane.co.uk/modernsteam/ldp/argentina/arg.htm
And Cesar Pelli, the modern architect, was born there...