Istanbul Tram

For a first Istanbul trip, the tram may matter more than the metro. The metro handles long jumps, but T1 is the sightseeing spine: Sultanahmet, Gülhane, Sirkeci, Eminönü, Karaköy, Tophane, and Kabataş all sit on the same practical line.

How I would use it

Use T1 when you are crossing between the old city and the Galata/Kabataş side and do not want to turn every movement into a taxi negotiation. It is especially useful for linking Sultanahmet, the Grand Bazaar edge, Sirkeci, the Spice Bazaar, Galata Bridge, Karaköy, and the ferry/funicular side around Kabataş.

The catch is crowding. T1 is exactly where everyone wants to be. With luggage, it is not graceful. For short hops in the old city, walking can be better than squeezing onto a packed tram for two stops.

Golden Horn layer

T5 is the newer Golden Horn tram. It is less universal for a first visit than T1, but it is the line I would look at for Balat, Fener, Eyüp, and the north side of the Golden Horn.

This is the transit piece that makes Istanbul's water geography easier to read: old city on one side, modern districts and ferry piers on another, then a separate Golden Horn corridor beyond "walk from Sultanahmet."