Phra Nakhon is one of the 50 districts (khet) of Bangkok. It is the central district of Bangkok, including Rattanakosin Island. Neighbouring districts are, from the north, clockwise: Dusit, Pom Prap Sattru Phai, Samphanthawong, and across the Chao Phraya River, Thonburi, Bangkok Yai, Bangkok Noi, and Bang Phlat.
Phra Nakhon was also the name of Bangkok Province, until it was merged in 1972 with Thonburi to form the present day Bangkok metropolis. The district is bounded by the Chao Phraya River to the west, Khlong Phadung Krung Kasem in the north, and Ratchadamnoen Road and Khlong Ong Ang to the east. The center of Bangkok, marked by the city pillar shrine (lak mueang), is in the district. Also surrounding the large open space of the Sanam Luang are the Grand Palace and Wat Phra Kaew, the National Museum in the former palace of the Vice King, and the main campus of Thammasat University as well as Silpakorn University.
Other significant landmarks in the district include Wat Pho, the Giant Swing, Wat Suthat, Wat Ratchanadda (with Loha Prasat), and the Democracy Monument. Also the well-known Khaosan Road is in the district. Another significant temple is Wat Bowonniwet, where several Thai kings were ordained as monks.
Of the original 14 forts protecting Bangkok only two survive. Fort Phra Sumen in the northern corner of the district, and Fort Mahakan in the east. Since 2000 a small park named Santichaiphrakarn around Fort Phra Sumen was built.
In 2005 the riverfront of the Phra Nakhon District, from King Rama I Bridge (Memorial Bridge) in the south to the Wasukri Pier (Dusit District), was submitted to the UNESCO for consideration as a future world heritage site.
Another landmark is Sala Chalermkrung Royal Theatre on Charoen Krung Road. It is Bangkok's oldest cinema and was the first air conditioned theater in Thailand. Built at the order of King Prajadhipok and named by him, it opened on 2 July 1933. It is the only theater from the first "golden age" of Thai cinema still standing. No longer regularly showing movies, the theater has been renovated and is principally used for Thai dance performances. Another point of interest is the Pak Khlong Talat flower market. Tha Phrachan pier is a well-known Thai amulets market.
Phra Nakhon was once an amphoe (district) named Chana Songkhram. The administration was overhauled on 15 October 1915 when 25 new amphoes were created for inner Bangkok. On 12 March 1928, six of these amphoes, Amphoe Phahurat, Amphoe Samran Rat, Amphoe Phra Ratchawang, Amphoe Chana Songkhram, Amphoe Sam Yot, and Amphoe Bang Khun Phrom were merged to form Amphoe Phra Nakhon. It became Khet Phra Nakhon in 1972.
Songkran, the traditional Thai New Year festival, is celebrated throughout the country from 13–15 April of each year. Khaosan Road (or Khao Sarn Road) in Phra Nakhon District is one notable place to celebrate the event where lots of people, both locals and tourists, come and splash water. During another famous festival, Loy Krathong, on the 15th day of the 12th lunar month, the Chao Phraya River bank in the district, with numerous piers and Phra Sumen Fort, is a popular place to float lanterns on the water.
Ratchadamnoen Avenue is often heavily decorated with lights around the king's birthday (28 July), the queen mother's birthday (12 August), National Day (5 December) and other major anniversaries. Sanam Luang and recently created Lan Plabpla Maha Chedsada Bodin in front of Wat Ratchanadda and its Loha Prasat are open spaces that frequently used to celebrate events.