Navitas Spa Merkezi, Mall Of İstanbul Hilton
For a visitor based in Sultanahmet, this is a trip out of the old peninsula, not a stop on a sightseeing loop. The spa is in the Hilton at Mall of Istanbul, in the İkitelli area of Başakşehir. It is open daily from 09:00 to 22:00, and 439 Google reviewers give it 4.8. What it offers is not confirmed: the website would not open, so treatments, prices, pool or hammam facilities and booking rules are all unknown. It is also unclear whether people who are not staying at the hotel can use it, so ask before you plan around it.