This is fibonacci island:

The Fibonacci island has got 3 sides, 3 roads and 3 parts

Why 3 ?

Because it's a Fibonacci series number.

The whole point and most interesting fact about Fibonacci Island is that everything on the island has got something to do with the Fibonacci series. What does that mean? Well, for example with regards to names, if your name has four letters than it doesn't exist on Fibonacci Island because four doesn't belong to the Fibonacci Series. However if you are called Maria or Mar, then you can live on Fibonacci Island because they have 5 and three letters respectively and 3 and 5 are Fibonacci numbers. Taking all of this into account, you should visit our island and see how the Fibonacci numbers affect our numerical land. Have a nice trip!