Şemsi Ahmet Paşa mosque complex, built by Sinan, the great architect, and a landmark that greats the traveler arriving by ferry, since it stands at the waterfront. It’s from 1580, the mosque is just one room with a dome. Part of the complex is used for a library and such. In front fishermen are busy at all hours I went there. Teahouses cater for the visitors. A great spot.