Sergio Fajardo
He first entered politics in 2003 when he was elected Mayor of Medellin , the second-largest city in Colombia and the capital of Antioquia . 
<triplet> Medellin <subj> Colombia <obj> country <subj> Antioquia <obj> located in the administrative territorial entity <triplet> Colombia <subj> Antioquia <obj> contains administrative territorial entity <triplet> Antioquia <subj> Medellin <obj> capital <subj> Colombia <obj> country