This intensive Italian discovery begins in the Eternal City of Rome, so you’ll probably want to arrive a few days early to take in the most iconic sites-from Vatican City, the Colosseum, and the Spanish Steps, to the Roman Forum and Trevi Fountain.In Porto Torres, on Sardinia, step back in time through the island’s many historic sites. Must-sees include the San Gavino Basilica-the island’s largest and oldest Roman church-and the ancient Aragonese Tower, built in 1325.