Old City Walls, Istanbul

Chora Church

Also known as the Church of St Saviour in Chora (chora translates 'countryside' in Byzantine Greek, which refers to what the site of the church exactly was when it was built), this is 1000 year old Byzantine church, an example of a church somewhat out of the traditional center, but is an absolute must see with precious mosaic frescoes and a captivating mood inside

Yedikule Fortress

This fortress in the very southwest of old city, next to the city walls was Porta Aurea, i

Fatih

Turkuazoo

One of those typical huge aquariums where you walk through transparent tunnels underwater

Eyüp Mosque Complex

This is the main attraction around this part of the city

Patriarchate of Constantinople

Arguably the centre of World Orthodoxy, housed since 1586 in Church of St George (Greek: Agíou Geōrgíou, Turkish: Aya Yorgi), which is, despite its religious importance, an otherwise unremarkable and unimpressive building from outside, though its lavishly decorated interior is worth a look

St Stephen Church

A Bulgarian Orthodox church better known as Demir Kilise, i

Feshane

Originally a factory producing fezzes (fes), Ottoman red hats made of felt, adopted in Ottoman Empire in early 1800s as a part of westernizing efforts in lieu of much more traditional turbans

Rahmi M. Koç Industrial Museum

This is a typical industry museum which showcases evolution of machines

Suleymaniye Mosque