Concierge.com's insider take:
For a complete detox after overdosing on Rome's classical wonders, take Metro Line B to EUR, the "model" suburb dreamt up by Mussolini and his Fascist urban planners. World War II halted work on the scheme, which was meant to host the 1942 Esposizione Universale Roma (World's Fair); the project was picked up later and significantly altered. Now largely a business district, EUR bustles from Monday to Friday, but on the weekends the deserted area becomes an eerie testament to Il Duce's delusions of grandeur. Check out Palazzo della Civiltà del Lavoro—nicknamed the "Square Colosseum"—and the imposing Palazzo dei Congressi. At the Museo della Civiltà Romana, a huge model shows what Rome looked like in its imperial heyday (10 Piazza Giovanni Agnelli; 39-06-592-6135; Tues.–Sun 9 am–2 pm). EUR's vocation for forward-looking architecture lives on today, with Massimiliano Fuksas' visionary new congress center—known as la nuvola (the cloud)—gradually taking shape.