Siam (Thai: สยาม, rtgs: Sayam, IPA: [sà.jǎːm]) is an area in the Pathum Wan district of Bangkok. It is a de facto district/neighborhood that consists of roughly 43 acres (170,000 m2) of the Thai Royal Family's estate, of which 17 acres (69,000 m2) is the Sra Pathum Palace; the remaining 26 acres (110,000 m2), formerly home to the Siam Intercontinental Hotel and its royal gardens, are leased by the Crown Property Bureau to several vast, upscale shopping complexes that are located on either side of Rama I Road. Though no district of Bangkok legally exists by the name "Siam," local Thais refer to this area as such, and consider it to be the very heart of Bangkok. Siam is connected to the adjacent Ratchaprasong area via a number of footbridges.
During the 4th reign of the present Thai dynasty (1851–1868), King Mongkut ordered the construction of a small palace for royal recreation in this area. The palace was built, and His Majesty named it "Pathumwan Palace," meaning "Lotus Palace". The Siam area was also the location of the nation's first airport.
When the Don Mueang Airport opened in 1914, the land was freed, and inherited by Prince Mahidol Adulyadej of Songkhla, the father of the present King. The prince ordered the construction of the Sra Pathum Palace ("Lotus Pond Palace.").
Sra Pathum Palace is situated on 17 acres (69,000 m2) of the Royal Estate's 43 acres (170,000 m2). The palace hosted the weddings of the Prince Mahidol Adulyadej and the Princess Mother in September 1920, and the current king and queen on April 28, 1950. The late Princess Mother formerly lived at the palace; it has recently been renovated to serve as the residence of the Princess Maha Chakri Sirindhorn.