We're searching for a geological rift or valley that's nearly 4,000 miles long as the crow flies.

More about crows and other birds in a minute.

It's the name of the rift or rift system that we're looking for... This one covers a lot of territory:

“Turkey Syria Lebanon, Israel, Egypt, Sudan, Ethiopia, Eritrea, Kenya, Tanzania Malawi, I think I'm going to lose it there. There are different ecosystems: Antiokia Lake in Turkey, the Hula, Galilee, Dead Sea, Nile, Soda lakes in Kenya."

Photo: http://flickr.com/photos/smsm89

Okay, so you get the idea. This rift stretches out along a north-south axis. You'll find some of Africa's highest mountains and deepest lakes along its path.

It also serves as a major migratory route. Hundreds of millions of birds fly over this rift - all the way from southern Africa to southern Asia.

It's a birdwatchers delight.

Try and name it if you can.