-Planning a visit to Expo Milano 2015 or simply touring in Milan are activities that require a certain amount of a priori knowledge of the city. In this paper, we present the process of building such a comprehensive knowledge base, the 3cixty KB, that contains descriptions of events, places, transportation facilities and social activities, collected from numerous static, near-and real-time local and global data providers, including Expo Milano 2015 official services and several social media platforms. Entities in the 3cixty KB are deduplicated, interlinked and enriched using semantic technologies. The 3cixty KB is empowering the Ex-plorMI 360 multi-device application, which has been officially endorsed by the E015 Technical Management Board and has gained the patronage of Expo Milano 2015, thus offering a unique testing scenario for the 20 million expected visitors along the 6 months of the exhibit. As of Septem-ber 7th, 2015 the 3cixty KB contains unique descriptions of 18, 665 events, 758 artists, 225, 552 places, 9, 342 transportation facilities, 95, 570 illustrating photos and 94, 789 reviews contributed by 81, 944 users. The 3cixty KB is accessible at http://3cixty.eurecom.fr/sparql while Ex-plorMI 360 at https://www.3cixty.com
