Rome is beautiful to in the daytime but it's incredible at night. Monuments like the Colosseum, the Trevi Fountain and St. Peter's Basilica are even more spectacular at night than they are during the day.
The Pantheon, the Spanish Steps, Fontana delle Naiadi, Palazzo delle Esposizioni, Piazza Venezia and Altare della Patria, Colle Capitolino, Fori Romani, Arco di Costantino, Circo Massimo, Castle Sant'Angelo, San Pietro, Villa Borghese, Piazza del Popolo, Via Veneto, Piazza Navona...
The distance from Lignano is about 600 km., ca. 5 hours by car. By plane is about 50 minutes flight.