It's interesting to contrast this with the Pizza Hut down the street from the Great Pyramids: http://imgur.com/PWtf3DV

curious what the surrounds of this look like https://m.flickr.com/deep/photos/54539963@N00/9557054418

or do watermelons grow in a desert?

Maybe somewhat counter-intuitively, vegetables & fruits like melons, watermelons, cucumbers, etc. (that contain a lot of water), often grow well in dry-looking sandy soil. I think it may be partly because the soil is loose, so their roots can go deeper more easily, to reach the water below. As a result, I've often seen and heard of these plants growing or being grown near rivers and lakes, even somewhat far away from the water's edge, because there is water below, in the water table.

Source: I did a lot of gardening in my teens and also read a lot about it.

They do when you water them. The Nile runs through the desert in northern Sudan.

Thank you for sharing!

The "hack" here, is merely getting the information out...historically not easy.