It only took us one hour to fly to Izmir. Our hotel in Istanbul was located close to the Hagia  Sophia, but you can easily find a hotel that is located further away as public transportation is  cheap, convenient and very practical in Istanbul. It allows you to avoid the taxis that  unfortunately have a bad reputation. We spent 4 days in Istanbul and visited some extraordinary  places like the Hagia Sophia. Originally it was a catholic basilica built around the 4th century CE.  In 1453, Sultan Mehmet II converted it into a mosque.Then in 1934, it became a museum. In   2020 under a new decree, it was converted back into a mosque. The mosque is very impressive  because of its size and despite several quakes, it is still standing thanks to much repair work. To  visit the place, you have to pay 25 Euro (before 2024, it was free). Let’s hope that the funds will  be used for more building restoration work. Many people visit this place, so go early. In the main  part of the mosque, there are some white curtains have been hung to hide the images of Christ.  They are splendid and if you go around the main place you can see what is behind the curtains. Not  far away from the Hagia Sophia, is the blue mosque, so called because of the color of the   ceramic decorations. This mosque is well-preserved and attracts a lot of visitors. It is the biggest  mosque in Istanbul and has 6 minarets. Mecca got upset because it had the same number of  minarets as the main Hajj mosque, but finally the row was resolved by building a seventh one in  Mecca. Access is free, but you cannot enter at prayer times.  Also not far from the Hagia Sophia is the Cistern Basilica. It has no religious purpose, but is  famous for the number of underground columns, of which there are 336 s (12 x 18) 8 meters tall  .   The ground surface area is 183 by 63 meters, and when full, it contains the equivalent of 6  Olympic pools, or 78 million liters of water. The purpose of the citerna  to retain the water  collected in the winter against the drought in the summer. It has been used in several films the  James Bond movie "From Russia with Love" and Dan Brown's "Inferno". In short, it is a must visit.  Istanbul is a city cut in two by the Bosphorus which separates Europe from Asia. In the Bosphorus  you can see many boats going in all directions. It is 32 kilometers long, but the narrowest place is  only 700 meters wide. The Bosphorus is the only link between the Black Sea and the  Mediterranean Sea. You can see all sorts of vessels, such as tankers, container boats, public  transportation boats and pleasure yachts. There is a continuous current on the surface where the  water flows to the Mediterranean Sea. Despite the number of boats, accidents are rare, and big  tug boats are always on standby to help a boat that needs assistance. The Bosphorus is truly  impressive, and you can visit it by  public transport, a restaurant boat or renting a private yacht  for 2 to 3 hours if you wish. On the European side of Istanbul, is the Grand Bazaar, a huge market that started to be built in  1455. Since then, it has suffered from earthquakes but has been quickly rebuilt and enlarged.  Today, there are more than 3,600 shops of all kinds, selling such items as jewelry, spices, fabrics, carpets, clothes, ceramics, silverware, etc..... Every day, more than 26,000 people work in this  place. Even if you have no intention to purchase anything, it is an interesting place to visit.  The last day in Istanbul, we took a ferry to the Prince Islands,  south of the Bosphorus. In around  1450, they were reserved for the Byzantine Princes, but this has changed, and now a lot of nice  houses have been built on them, several built completely of wood. To move on the island, you have  to use your legs, or you can use public transport. The place is so quiet that it is not difficult to  understand why the people of Istanbul like to come here on holidays.