There are five gyres in the world's oceans. What's a gyre, you might ask. I thought the same thing when I first came across the concept.
The Mother of All Mothers | The Gyres of the Oceanic Circulatory System

There are five gyres in the world's oceans. What's a gyre, you might ask. I thought the same thing when I first came across the concept.
Over four thousand years ago, the Persians came up with an ingenious method of irrigation known as the qanat.