So the island of Faisans is in France/Spain. Yes, both.
For six months of the year, from February 1st to 31st July, it's under Spanish rule - and for the following six months - it's under French control.
So my question - do you need a Spanish visa during the 'Spanish time' and a French visa during the 'French time', in order to visit it, or given they sorta share the island, would either work?
(Yes I realise they're both Schengen countries, but it is also possible for one to get a visa for a particular country. Yes I realise it's probably not guarded and nobody cares, but I'm interested in trivial laws like this and the long-term effects they might have.)