Four days in Istanbul
Long enough for the city to stop being a list of monuments and start being a place.
Day 1 — All of Sultanahmet, without rushing Topkapı.
Day 2 — Bazaars in the morning, Galata and Karaköy in the afternoon, walking up to İstiklal.
Day 3 — The Bosphorus by boat and the Asian side: Üsküdar and Kadıköy.
Day 4 — Balat and Fener at walking pace, the cable car to Pierre Loti, and a free last afternoon — which is usually when people go back to whichever place they liked best.
A fifth day buys the Princes' Islands.