Mosques have fountains where worshippers wash their feet and hands and face and perform other ritual ablutions before going to pray. I only saw men at these fountains.
This particular one was not in use.
Click on these two photos for detail and note the beautiful Arabic calligraphy at the top of the second one.
A couple of minutes' walk from Haghia Sophia (which was first a church, then a mosque, and is now a museum) is the tram on a very touristy street with, you guessed it and you see it, Starbucks.