Whether or not they're still inhabited by people who have chosen a devout way of life, convents have a calming aura about them. Head to Convento de San Francisco and feel the spirituality around you.
You'll find this community of nuns in La Rioja. Once you've done everything you want to at Convento de San Francisco, have a look at nearby Cathedral San Nicholas de Bari, Plaza 25 de Mayo, and Museo Folklórico.