Signing of the Treaty of Concordia So the island was split into two parts and shared by France and Holland. The French occupied the northern part (20 mi?), the Dutch the southern part (13 mi?). As history tells it, the dividing line was determined by two walkers, a Frenchman and a Dutchman.

The island of St. Martin is unique for being the smallest inhabited island in the world divided between two sovereign nations: France and the Netherlands. The northern, slightly larger portion is known as Saint-Martin and is an Overseas Collectivity of France. The southern portion is known as Sint Maarten and is a constituent country of the Kingdom of the Netherlands. Despite being divided since the Treaty of Concordia in 1648, there is no physical border or "hard" customs check between the two sides, allowing for the free movement of people and goods, which is a major draw for tourists. The French side is famous for its "French Riviera" vibe, gourmet dining in Grand Case, and nude beaches, while the Dutch side is known for its vibrant nightlife, casinos, and the famous Princess Juliana International Airport where planes fly low over Maho Beach. In 2026, the two halves continue to share infrastructure and cooperate closely on tourism marketing, maintaining a peaceful dual-nationality that has lasted for nearly four centuries.