Pheasant Island (French: Île des Faisans/Île de la Conférence, Spanish: Isla de los Faisanes, Basque: Konpantzia, Faisaien Uhartea Konferentziako Uhartea) is an uninhabited river island located in the Bidasoa river, located between France and Spain, whose administration alternates between the two nations every six months.

This was the climax to a series of 24 conferences held between Luis Méndez de Haro, a grandee of Spain, and Cardinal Mazarin, Chief Minister of France, in 1659 following the end of the Thirty Years' War.

The island is a condominium,[3] the world's smallest,[4] under joint sovereignty of Spain and France;[5] for alternating periods of six months, it is officially under the governance of the naval commanders of San Sebastián, Spain (1 February – 31 July) and of Bayonne, France (1 August – 31 January).

[8] In practice, it is administered in turn by the mayors of Irun (in Gipuzkoa, Spain) and Hendaye (in the Pyrénées-Atlantiques, France).

[9] Other than that, employees of the municipal government of Irun or Hendaye may access the island once every six months for cleaning and gardening,[12] and members of the Naval Commands of San Sebastián (Spain) and Bayonne (France), responsible for monitoring the island, land on it every five days.