The day of the handover, which happens twice a year, is one of the rare occasions visitors are allowed to visit this 200-metre-long island, one of only a handful of condominiums in the world.
ADVERTISEMENTPheasant Island, the world's smallest territory with joint custody, will swap its nationality from Spanish to French on Wednesday in a biannual handover.
Irun, Spain and Hendaye, France are responsible for looking after it for six months of the year each as a series of protective measures have been taken to stabilise its land area in the Bidasoa river.
From 1 February until 31 July, Spain holds stewardship of the condominium — a term used to refer to a political territory in which multiple sovereign powers formally agree to share equally. The other six months onward, this small island becomes an official part of France.
This singular event occurred following a ceasefire at the end of the 1618-1648 Thirty Years War between these two countries, when it was designated as a neutral space to delimit the new borderlands.
The 200-metre-long island was turned into a peace metaphor.
The evolution of Pheasant Island's name
The tiny island has many names. In Roman times, it was known as Pausoa, the Basque word for passage or step.
Then, the French translated this as Paysans, meaning peasant, before switching it to Faisans, meaning pheasant.
"In Basque, some continue to call it Konpantzia, a name which undoubtedly derives from the meetings which were held on the island during the 17th century," Basque Country Tourism's website says.
Visitors are only allowed onto the island on very few occasions. These include the handover days, when the island holds an official ceremony with flags, delegates, diplomats, and plenty of formal pomp, or as part of heritage tours.
Where to find the other condominiums?
Currently, there are only a handful of condominiums in the world.
In Europe, Lake Constance is a tridominium between Austria, Germany and Switzerland.
Another is the Moselle River and its tributaries, the Sauer and the Our, a condominium shared by Germany and Luxembourg.
Then there is the Joint Regime Area, a shared maritime zone between Colombia and Jamaica, that was established through a bilateral agreement that was reached in 1993 but did not enter into force until 1994.
And there is also the Abyei Area contested by South Sudan and Sudan.
The Gulf of Fonseca is another tridominium portioned up by Honduras, El Salvador and Nicaragua.
ADVERTISEMENTAntarctica is the last but also the largest and most important theoretical continental condominium governed by the 28 signatories of the 1959 Antarctic Treaty.