Istanbul is a city with endless things to see and do, but if you’re short on time, 3-4 days is a good start. The first day can be all about Sultanahmet, visiting Hagia Sophia, Blue Mosque, and Topkapi Palace. On the second day, explore Beyoğlu—walk along Istiklal Street, visit Galata Tower, and take a ferry to Kadıköy. I struggled with planning my itinerary, but after browsing https://istanbulpoints.com/, I found some great suggested routes. They had sample itineraries for 2, 3, and 5 days, which helped me maximize my time and not miss any key attractions.
