A map of the Falkland Islands dispute.
The Falkland Islands held a referendum this week to decide whether they wished to remain a part of the United Kingdom (they did, overwhelmingly). Argentina has long claimed ownership of the islands (which are controlled by Britain) and the standoff between the two countries has grown tense of late.
That's due, in part, to the discovery of potentially significant amounts of oil in the waters around the islands. Indeed, the estimated 8.3 billion barrels of oil believed to be off-shore amounts to triple Britain's current reserve.
Argentina and Britain are both signatories to the UN's Convention on the Law of the Sea, which spells out various ownership and legal rights to territorial waters and the natural resource wealth therein. The folks at Political Geography have put together the useful map above which highlights the various claims.