Private islands come in all shapes and sizes and can cost anywhere from $200,000 to $200 million, depending on what you're looking for. However, buying an island and building on it is a major investment of both time and money, so it's important to find the right one that's worth waiting for.

Virtually all islands in the world are claimed and governed by some national government. That nation's laws apply, and any attempt by the owner to claim sovereignty would generally be unrealistic.

There are tens of thousands of private islands in the world, ranging from a few dozen square feet to hundreds of square miles. Usually, they are governed by the laws of a nearby country but restricted to use by the owner alone.

The entire eastern seaboard of North America is dotted with private islands, from Nova Scotia in the north all the way down to the Florida Keys.