
This is a hooka. It is a water pipe that is used for smoking shisha. Shisha smoking is a favorite pastime all over Cairo. There are shisha places everywhere. Many restaurants offer shisha for after-meal relaxing.
The tobacco is placed in a clay cup at the top of the pipe, then covered with aluminum foil punched with holes. Hot charcoal is placed on top of this -- just a few very hot pieces. When you draw on the pipe it lowers the pressure in the water chamber and the hot tobacco smoke is then cooled as it passes through the water, then through the long pipe to the mouthpiece. (You purchase a new mouthpiece each time--they are cheap.) The attendant comes around periodically to renew the hot charcoal.
There are many flavors of tobacco commonly used here. The one I smell the most often as I walk by, is the apple flavored, but there is mint, and watermelon, among others.

These men are enjoying shisha after their meal. You can see lots of shisha pipes if you look carefully.

Shisha pipes are for sale. Almost nobody smokes shisha at home when it is so easy and cheap to smoke in a shisha place. These pipes are not very hardy so they need replacing often. They are glass and they break. The tubes and pipes wear out.
One of the small charcoal fires going in a pan on the street getting ready for use in the shisha pipe.

An attendant bringing around the shisha to customers. You can see the few bits of charcoal in the top. See the little clay pot the tobacco goes in and the charcoal on top. This charcoal has cooled a bit, and needs renewing.

Shisha is not for men only. Women enjoy shisha as well. Often in restaurants you see couples smoking shisha, as well as groups of women smoking.
I haven't tried it yet. I quit smoking over 20 years ago and just can't bring myself to try this stuff. It isn't something that appeals to me. But millions of Cairenes love it.