The third courtyard's most beautiful section is the Treasury. It consists of four different halls which are located on the eastern corner of the Third Courtyard. These rooms were used as a suite of reception rooms by some of the sultans.

Hall 1: The most notable exhibit here is an ebony throne inlaid with ivory and mother-of pearl, made for Murat IV. The other pieces are nargilahs (water pipe) with cut-crystal bases and mouthpieces set with diamonds; little coffee cup holders, including one set with rose-coloured diamonds and enamelled gold-pen box decorated with gems. Various Holy Koran holders are also worth seeing. There is also an armour of Sultan Mustafa III, which is quite impressive. It is made of iron and decorated with gems. It is a protection from top to toe.

Hall 2: This room is known as "Emerald and Emerald Objects Section".Upon entrance, there is a hanging pendant belonging to Sultan Abdulhamit I of emerald and golden framed. This is one of the most striking pieces in the exhibits. In the same case is a six-sided pendant of emerald belonging to Sultan Ahmet I. The body sits on a six pearl foot, with each of its six sides framed in gold. The cover is domed in a gold lattice, encrusted with diamonds and sapphires. The old plaque at the base indicates that it was commissioned by Sultan Ahmet I. in the year 1617 at a price of 6000 gold pieces. In the lower corner of this case, on a turban, is a 17th century plume-decorated with two five centimeter emeralds in length, formed on a heavy gold pin. Its top is decorated with two five centimeter emeralds and a garnet stone, framed by diamond-encrusted gold leaves, and loops of pearl chains. An additional pendant in this same case was commissioned by Sultan Ahmed I.

In the third case, at the top, is an emerald pendant belonging to Sultan Mustafa, and an emerald dagger belonging to Mehmet IV. This dagger is a fine example of 17th century craftsmanship, 31 centimeters in length, its handle of solid emerald, worked in gold an other precious gems. It was a present to the Sultan Mehmet IV. at the dedication of the Yeni Mosque.

Hall 3: In this hall, more diamond and gold works are displayed. In the case on the right of the entrance are Koran covers decorated in precious stones. in the second case is a dessert set belonging to the Sultan Abdulhamit, as well as a gold incense burner, and an enameled sherbet set.

At the top of the third case is a pendant carrying the seal of the sultan Mahmut II.,of diamonds, on a blue and pink enamel background. The chain is made of gold, and the tassel 45 strings of 38 centimeters of pearls. In the same case is a grouping of several very large, very famous cut diamonds. The broaches, rings ad other jewelry items here are equally lovely. In the fourth case, of particular note are the gold tray and gold incense burner.

In the fifth case, perhaps this room's most beautiful object, the Kasikci (spoonmaker's) diamond, is located. This diamond is 86 carats and surrounded by 49 brilliants. This is the diamond which the 1960s famous movie "Topkapi" was about.(Topkapi, starring Melina Mercury)

Hall 4: The central object of this room is the Turkish and Indian masterpiece in its center, the throne of Mahmut I. A gift of the Persian King Nadir Shah, on a green and red background, its designs are of emeralds and pearls. On the right in a case, are pots and ivory mirrors. Across, in a large number of cases, are swords, rifles, prayer beads, spoons, all beautifully decorated. There is also a  box in which the mantle of the Prophet Mohammed was once kept.