San Marino or the Serenissima Repubblica di San Marino to give it its full name is a mountainous micro-state in Europe surrounded by north-central Italy. Among the world’s oldest republics, it retains much of its historic architecture. On the slopes of Monte Titano sits the capital, also called San Marino, known for its medieval walled old town and narrow cobblestone streets. The Three Towers, castlelike citadels dating to the 11th century, sit atop Titano’s neighboring peaks.