The Centre of the World
In a world with four large continental land masses positioned at the cardinal orientations and a group of islands in the middle, it is not hard to spot the exact centre of everything. A few calculations here, some finely-tuned cartography work there, and The Centre of the World becomes global knowledge. And, in this particular case, a tiny island with otherwise bland features becomes one of the busiest touristic spots in the world. The Centre of the World is located inside an island of barely 1000 km2 inside the Central Islands Federation. It didn't even have its own name before it got branded "The Centre of the World", and now why bother calling it anything else? Humans are particularly persuaded by its important-sounding name, and thus make up 90% of the applications to get the special visa needed to enter the island (though it helps that until a decade ago, humans were the only ones allowed in The Centre of the World anyway). This special visa is a bureaucratic necessity that is, unfortunately, actually necessary. The island is too small to accommodate the huge number of people who want to brag about being in the Centre of the World (and who definitely want to take at least one photo next to the worn-out sign saying "You're now at The Centre of the World" while making some cliche pose). The island itself is protected by special fences on land and sea, and the island closest to it set up a "border control" that only lets in people in groups of up to 100 at a time. The journey to The Centre of the World takes 20 minutes with the purpose-built boats and a little walking. The 100 visitors have 1 hour to take as many pictures as they want before they're rounded up and taken back to the border control, and the next group is let in. The special visa comes with a specific date and time, which must be adhered to precisely, or the trip (and the visa fee) will be wasted. The Central Island Federations is very aware that this is a potentially unfair policy, but since they make considerable money out of people who missed their slot and have to apply for the visa again, they are not going to change it anytime soon.
Fauna & Flora
The Centre of the World is 1000 km2 of green grass that is regularly cut so that it looks pretty for the visitors. The only animals allowed there are birds, and that's only because it is too hard to keep them from landing on the island. Insects and other tiny creatures of no real consequence to human life are also allowed to live there, again because it's too much work to keep them out.
One can argue that the metal sign indicating The Centre of the World is the island's only natural resource. As long as one is persuaded by the argument that it is said sign that brings the thousands of tourists each day, and is thus what gives the islands nearby a reason to exist or be economically active.