Dolmabahçe Palace located in the Beşiktaş district of Istanbul, Turkey, on the European coast of the Strait of Istanbul, served as the main administrative center of the Ottoman Empire from 1856 to 1887 and from 1909 to 1922.
Dolmabahçe is the largest palace in Turkey. It has an area of 45,000 m2 (11.1 acres), and contains 285 rooms, 46 halls, 6 baths (hamam) and 68 toilets.
The design contains eclectic elements from the Baroque, Rococo and Neoclassical styles, blended with traditional Ottoman architecture to create a new synthesis.
The Dolmabahçe palace is extensively decorated with gold and crystal. Fourteen tonnes of gold were used to gild the ceilings. The world's largest Bohemian crystal chandelier is in the Ceremonial Hall. It has 750 lamps and weighs 4.5 tonnes.
Dolmabahçe has the largest collection of Bohemian and Baccarat crystal chandeliers in the world. The famous Crystal Staircase has the shape of a double horseshoe and is built of Baccarat crystal, brass and mahogany.
According to en.wikipedia