1Sultanahmet
Sultanahmet is the classic old centre, with Hagia Sophia, the Blue Mosque, the Basilica Cistern and Topkapı Palace within walking distance. There are many small and mid-sized hotels in historic buildings here. The main advantage is easy access to the headline sights, while the drawback is that the area feels quieter and less local in the evening.
2Beyoğlu and Galata
Around Galata Tower, İstiklal Avenue and the steep streets down to the water, you stay in the middle of a busy, creative city district. Expect design hotels, boutique addresses and larger city hotels. It suits travellers who care about restaurants, bars and evening walks, but be ready for hills, traffic and noise on the busier streets.
3Karaköy
Karaköy sits where the Golden Horn meets the Bosphorus, between the old city and Beyoğlu. It feels compact, well connected and energetic, with cafés, bakeries, galleries and hotels ranging from sleek modern stays to smaller boutiques. It is a strong base if you want to use trams and ferries often, though the main roads and port area can be busy.
4Kadıköy
Kadıköy, especially around the market and waterfront, shows you a more everyday side of Istanbul. You stay among food spots, bars, bookshops and residential streets, with plenty of life but less sightseeing pressure. It is ideal if you have been to Istanbul before or deliberately want to stay outside the tourist core, though you rely more on ferry or metro for the main landmarks.
5Beşiktaş
Beşiktaş is a real city neighbourhood on the water, popular with students, commuters and locals heading out to eat. It works well for Dolmabahçe Palace, the Bosphorus and northern districts such as Ortaköy. Hotels are mixed, from simple city stays to more upscale addresses, but traffic can be intense and transport often depends more on buses or taxis than on trams.
6Şişli and Nişantaşı
If you prefer a modern, less touristy base, Şişli and especially the area around Nişantaşı work well. Expect broad streets, shops, cafés and larger hotels with a more international, business-like feel. It is convenient for the metro and for a polished, comfortable stay, less convenient if you want to walk straight to the historic sights.