Guaita Tower in San Marino (© Piercarlo Abate/Shutterstock)

Guaita Tower in San Marino (© Piercarlo Abate/Shutterstock)

In the 'Most Serene Republic'

Though some of the details of the founding of San Marino vary depending on who is telling the story, what's certain is that in the 4th century CE, a stone mason built a Christian chapel on a hill near the Mediterranean coast and founded the settlement that would share a name with Saint Marinus. Over the centuries European nations grew, shrank, and changed—but San Marino remained, ultimately bordered on all sides by Italy. Today, this tiny nation, sometimes called the Most Serene Republic of San Marino, celebrates 1,718 years of existence and its continued status as the world's smallest republic—24 square miles of quaint European charm embedded in Italy's northeastern region.