- The Saint Sophia Basilica: built during the Byzantine Empire in 537, the basilica was transformed into a mosque after the fall of Constantinople in 1453 at the hands of the Ottomans. Four minarets were added. There are still golden mosaics, characteristic of Byzantine art.
- The Basilica-Cistern: built in 530 AD, this amazing and gigantic construction provided water to the imperial palace. The cistern was built underground and has a capacity of 20,6015,419 gallons.
- The Blue Mosque: it was named for the color of the mosaics that decorate the inside of the building. The Blue Mosque, or Sultanahmet Camii is the only mosque in the world with 6 minarets. It is a recent building because its construction dates back to the 17th century. Its architecture is inspired by both Byzantine art and Ottoman buildings.
- The Topkapı Palace: building of Ottoman origin, the palace replaced Byzance's acropolis. It is surrounded by 3 miles of ramparts and overlooks the Golden Horn, the estuary that joins the Bosporus and the Marmara Sea.
Other lesser-known monuments are worth visiting, such as the Soliman the Magnificent mosque or the small Saint Sophia.
The shores of the Bosporus can be admired during a boat cruise, and they offer views of sumptuous buildings such as the Dolmabahçe Palace and the Beylerbeyi Palace.
Istanbul has many important archeological museums.
Go to the Grand Bazaar with its 4,000 shops for a relaxing break. The galleries alone are worth seeing. The Egyptian bazaar, also called the spice market, is the ideal spot for souvenirs during your trip to Istanbul.