An evening in Istanbul

Calculate the times carefully. If you're flying in and out of the Ataturk airport, with luggage checked through, then a 17:30 landing would get you to the airport gates around 18:30. A taxi downtown uis about 45 minutes, so you'll arrive 19:15 or thereabouts. Then you'd need get a return taxi at 21:00 to be back at the airport by 21:45. You've really got less than 2 hours.

If I were you, I'd get a taxi to drop you outside the blue mosque and aya sofia. Even if they're closed, they're actually most impressive from the outside anyway. Walk through the gardens and head downhill towards the sea, where you'll find a wide choice of cafes with outside seats and pleasant views.

I took my 4 children (then aged 3, 5, 9, 11) to Istanbul. We had a great time.

I wouldn't even attempt it.

Not sure if as a resident of Thorn Tree World you also need to purchase a visa for your 2 hour stay!!

Yes, #3 that could be an expensive consideration too! I wouldn't do it on such a tight turnaround.

If Op's origin or destination is in TK they may have to buy a visa anyway.

The good part about this is by the time OP arrives in the airport, you know if you're delayed or not. So you can choose to go downtown if you have time, and stay in the airport if time is tight.

For my perspecitve, I'd happily pay GBP 10 to be downtown for a couple of hours, even though I've seen it before. Better than spending 5 hours in an airport.

Thank you everyone for your suggestions.
1. i have no problem paying the 10 GP visa because i am currently resident in Lattakia -Syria which is an hour away from the
Southern city of Hatay (Antakya), since the visa is usually multi entry and valid for 3 months ( i think) then i can find ways to utilize the visa.
2. As for the times I have in Istanbul, ihave already deducted 2 hours for check in and exit from the airport so i hope to have at least 2 hours in the center of istanbul. I had to spend 3 hours in the airport on the way to Poland and my son got bored stiff, i think htat he will enjoy a walk along the Bosphorus shore especially as the Tirks are very friendly to children.
Again, thank you for taking the time to share you tips, if you can think of anything else i would really appreciate that.

In that case, I suggest that you head straight to Sultanahmet (30-60 minutes trip depending on traffic flow). Check out the Blue Mosque and the ancient hamam right next to the garden in front (the Agia Sophia could be closed in the evening), roam the shopping streets of Divan Yolu and have some tea and narghile at the Hippodrome. If you're hungry, head to the famous Tarihi Selim Usta Sultanahmet Koftecisi at 12, Divan Yolu for a quick fix. Its koftes are perfect and cheap.