The first which is immediately opposite the gate is the Throne Room or the Audience Hall. Here the sultans receive the ambassadors and high ranking state officials such as Grand Visier or the Visiers. Right behind the Throne Room there is the library built by Ahmet III (1703 - 30). On the right side of the Third Court, there is the barracks of the Enderun and the Privy Treasury which is also known as the Mehmet the Conqueror Pavilion. On the side facing the Fourth Court, there is the Larder Barracks of the Enderun, the

Treasury Chamber and the Chamber of the Sacred Relics.The left side starts with the Harem. The harem which covers a large part of the Palace consists of about 60 spaces of varying sizes. The main structures which are located in front of the Harem, facing the Third Court are Akağalar Mosque, Sultan Ahmet Mosque, Barracks of the Sacred Relics Guards and Chambers of the Sacred Relics. Here, the sacred relics brought back by Sultan Yavuz Selim from Egypt in 1517 are kept. The Fourth Court is entered from a covered path going from both sides of the Treasury Room. Here the buildings are located in the first part of the court, which has two sections of different levels.
On the left side of this section called Lala Garden or Lale Garden there is Mabeyn which is the beginning point of Harem's access to the garden, terrace for the ladies with removable glass enclosure, Circumcission Room, Sultan İbrahim Patio and another one of the symbols of Topkapı palace, the İftariye (or Kameriye) and Baghdat Pavilion. This pavillion was built by Murad IV in 1640 to commemorate the Baghdat Campaign. At the center of the first section of the Fourth Court, there is the Big Pool and Ravan Pavillion next to it. This pavillion was also built by Murad IV in 1629, to commemorate the Revan Campaign. The side facing the second section has Sofa Pavilion (Koca Mustafa Pasha Pavilion), Başbala Tower and Hekimbaşı (Chief Physician) Room. The Sofa Mosque and Esvap Chamber and the latest built Mecidye Pavilion are on the right hand side of the Fourth Court. Out of the pavillions built on the shore of the Marmara Sea, only Sepetciler Mansion has survived until the present.
During 18th. Century when the Topkapı palace took its final shape, it was sheltering a population of more than 10.000 in its outer (Birun) and inner (Enderun) and Harem sections. It shows no archirectural unity as new parts were added in every period according to the needs. However, this enables us to follow the stages Ottoman Architecture went through from the 15th to the middle of the 19th century at the Topkapı Palace. The buildings of the 15th - 17th centuries are simpler and those of the 18th - 19th centuries, particularly in terms of exterior and interior ornamentation are more complex.
Topkapı Palace was converted to a museum in 1924. Parts of the Palace such as the Harem, Baghdat Pavilion, Revan Pavilion, Sofa Pavilion, and the Audiance Chamber distinguish themselves with their architectural assets,while in other sections artifacts are displayed which reflect the palace life. The museum also has collections from various donations and a library.