Island Changes Flags: Tiny territory Between France and Spain Swaps Sovereignty Every Six Months
A small, uninhabited island in the Bidasoa river, marking the border between france and Spain, uniquely alternates nationality twice a year. Pheasant Island (Isla de los Faisanes/Île des Faisans/Konpantzia) operates under a condominium agreement, with Spain exercising sovereignty from Febuary to July, and France from August to January.
The 200-meter-long, 40-metre-wide island’s unusual arrangement stems from the Treaty of the Pyrenees in 1659, which concluded decades of conflict between France and Spain.The treaty established the island as neutral ground, famously hosting the marriage of King Louis XIV of France and Maria Theresa of Spain – a union that cemented peace. It afterward became known as “The island of marriages” due to further royal meetings held there in the 18th century.
Despite its name, Pheasant Island has never been inhabited by pheasants. Geographically, the island is technically a Spanish enclave, as the Bidasoa river’s main course – defining the Franco-Spanish boundary – runs along its northern shore.
Currently closed to the public, the island is maintained by officials from both countries on a rotating basis.Access is restricted, limited to municipal government employees from Irun (Spain) and Hendaye (France) for maintenance every six months, and naval personnel from San Sebastián and Bayonne who visit every five days.
Today, the island faces erosion challenges, prompting collaborative protective measures between France and Spain to stabilize its land area, including reinforcing embankments and ongoing monitoring. Pheasant Island is one of eight such condominiums worldwide, alongside Lake Constance (shared by Austria, Germany, and Switzerland) and the Brčko District (shared by Bosnia and Herzegovina and Republika Srpska).
