Land easy, walk the old city by dusk
Land in Istanbul and base yourself in Beyoglu, around the Karakoy or Taksim area. Sultanahmet has the major sights, but this side of the Golden Horn is where the city actually lives, better restaurants, more local energy, and easy tram or ferry access to the historic peninsula. Drop your bags, get water, get acclimatised. If you are arriving from a nearby time zone, you will have most of the day ahead of you. Use it gently.
Start at Hagia Sophia in the late afternoon when the tour groups thin out. Built in 537 under Justinian, it was the largest cathedral in the world for nearly a thousand years before becoming a mosque, then a museum, then a mosque again. The dome still feels improbable from below. Note: the ground floor is an active mosque (free, shoes off), but the upper gallery with the Byzantine mosaics requires a separate EUR25 tourist ticket. Allow ninety minutes inside.
Across the square is the Blue Mosque, free to enter outside prayer times. Beneath you, signposted from Hagia Sophia, is the Basilica Cistern, a sixth century underground reservoir with 336 marble columns standing in shallow water. It makes a good last stop before dinner.
Walk across to Karakoy for dinner, the food scene here is genuinely good and far less tourist-oriented than Sultanahmet. If time is tight, Eminonu on the way back works too. Tomorrow goes wide.
