Trams are pretty nice looking in Istanbul. On the Asian side you have a heritage tram, olde-worlde in style. There’s another on the European side as well, as well as a swanky looking modern tram.
There are 5 lines in total, and you can use the same transit pass for all of the lines as well as on other forms of public transport. Jetsons (tokens) costs 3 TL.
The T1 tram goes over the Galatta Bridge, so you get to see both the historical as well as the modern part of Istanbul. T1 Trams run from 06.00 to 23.50, every 5 minutes.
Take your camera; you’ll get some great views out of the window.