Among the smallest countries in the world, 24-square-mile San Marino also claims to be its oldest republic. And, indeed, this enclave in north-central Italy, essentially a remnant of the Boot’s medieval city-state network, has been a sovereign entity since the dawn of the 4th century CE—somehow resisting invasion and dissolution throughout the many tumultuous eras since.

Entirely surrounded by Italy—specifically Emilia Romagna and Marche—San Marino lies on the seaward slopes of the Apennines, only a stone’s throw from the Adriatic seacoast. Nearly 2,500 feet high, Mount Titano is a mighty limestone landmark of the republic: And its triple summits are accented by the Three Towers of San Marino.

The birth of San Marino in 301 CE came about when Saint Marinus, a stonemason, fled with his followers to Mount Titano to escape the Roman emperor Diocletian’s persecution of Christians. Despite the best efforts of various feudal lords and other rivals, and through such upheaval as Napoleon’s invasion of Italy, the Congress of Vienna, and the Italian Unification, Saint Marinus’s enclave—which formally became its own city-state in the 12th century—persevered on its fortified mount.

The views of and from Mount Titano are magnificent, and the historic landmarks of the City of San Marino—including its fortifications, its churches and cathedrals, and the Palazzo Pubblico—are popular destinations. During summer, the Palazzo Pubblico’s defenders, the Guardia di Rocca ("Guard of the Rock"), perform a well-known changing-of-the-guard ceremony on the half-hour—its own tourist attraction.

San Marino’s a unique holdout of another era, an anachronistic city-state redoubt occupying a small but scenic pocket of long-defended Apennine territory. It’s not big enough exactly to warrant a standalone visit, but including this venerable republic on an Italian tour is well worth it.

9 things not to miss.

  1. all three Towers of San Marino
    Walk to all three Towers of San Marino
    all three Towers of San Marino, San Marino
  2. Stand in Piazza della Libertà
    Stand in Piazza della Libertà
    Stand in Piazza della Libertà, San Marino
  3. the changing of the guard
    Catch the changing of the guard
    the changing of the guard, San Marino
  4. Palazzo Pubblico
    As noble as this government building is, it’s even more impressive when its colorfully outfitted defenders conduct their summertime Changing of the Guard.
    Palazzo Pubblico, San Marino
  5. Basilica di San Marino
    This Neoclassical church, built in the 1830s, serves as the spiritual heart of the tiny republic.
    Basilica di San Marino, San Marino
  6. National Museum
    This museum houses a rich collection of San Marino artifacts—and treasures from far beyond.
    National Museum, San Marino
  7. Monte Titano
    The country’s signal mountain brandishes the famous Three Towers of San Marino—the Guaita, Cesta, and Montale—on its peaks.
    Monte Titano, San Marino
  8. Museum of Torture Instruments
    Take a grim but irresistible tour of some of history’s most devilish torture devices at this singular stop.
    Museum of Torture Instruments, San Marino
  9. St. Francis Museum
    Vintage frescoes and other religious artwork and artifacts catch the eye at this museum, housed in a 14th-century church.
    St. Francis Museum, San Marino