Pheasant Island is a sliver of land in the Bidasoa, the river that marks the border between France and Spain, a couple of hundred metres long and about forty wide. A river island on the border is a good place for two kingdoms to meet, and in 1659 France and Spain negotiated and signed the Treaty of the Pyrenees there. Today the island is Spanish from the first of February to the end of July and French for the rest of the year. The naval commanders in San Sebastián and Bayonne look after it, and there is a small ceremony each time it changes hands. It was useful because it lay exactly in between, and the arrangement keeps it there: each country owns it for half the year, and neither for long enough to make it home.