Crazy, crazy cross-border maps

I have been browsing the back entries on the excellent Strange Maps blog (already mentioned below), and found this entry (http://strangemaps.wordpress.com/2006/09/11/6-market-reef/#more-16) on an island jointly shared by Sweden and Finland, with a surreal border running across the island. Of course, being in the Nordic region, there is a perfectly sensible and pragmatic reason for the border. The island is also the westernmost point of Finland, which is pretty useless - but nevertheless strangely compelling - information.