After we handed over our belongings at the bus station, we took a taxi to the city center, where it was planned to see the sights. In principle, it was cheaper to go by metro, as the taxi driver charged us as much as 30 liras, but the truth was not close to hagia Sophia. In general, after about 30 minutes, we were already walking around the old part of the city. Narrow streets, not tall houses, silence. Everything is conducive to a good walk and sightseeing. After we handed over our belongings at the bus station, we took a taxi to the city center, where it was planned to see the sights. In principle, it was cheaper to go by metro, as the taxi driver charged us as much as 30 liras, but the truth was not close to hagia Sophia. In general, after about 30 minutes, we were already walking around the old part of the city. Narrow streets, not tall houses, silence. Everything is conducive to a good walk and sightseeing. 
What can you see in Istanbul in one day?
– Of course Hagia Sophia! This is the main attraction of the city! You can easily spend half a day there. The cathedral is big and it is interesting to walk around it! By the way, the entrance there is paid and is not cheap, namely 20 liras, i.e. 10 dollars. The cathedral is stunning in its grandeur. And there was a queue to get in there. Here are a couple of photos of the cathedral: 
Swipe your hand 360 degrees, inserting your thumb into the hole and get good luck :-). To make it a queue, we were too lazy to stand: 
– Blue Mosque! Another iconic landmark in Istanbul. It is located next to the cathedral. There's everything nearby :-). Entrance there is free, only you will have to take off your shoes. In general, the mosque was not very impressed, but for a tick I recommend going there, especially since it is nearby. Here are a couple of photos of the blue mosque: 
– Grand Bazaar! Then we still managed to visit the big bazaar. On the map, it is usually marked as Grand Bazaar. Overall, it's a big big market. I do not recommend buying anything there, as they will definitely deceive! Well, or you need to be very well versed in the prices and quality of the thing that you plan to buy. There is no market for photos. After we saw all these sights, we still had time to walk through the park, which was nearby. Parrots flew there).). So just on the trees you could see multi-colored poop. For dessert, a couple more photos of Istanbul: 
Tips: – Upon arrival in Istanbul – buy a guide card, where the sights are marked. – In the big bazaar, you should buy only those things in which you are 200% versed, otherwise they can slip a marriage.