Shuri Castle History . The date of construction is uncertain , but it was clearly in use as a castle during the Sanzan period ( 1322 – 1429 ) . It is thought that it was probably built during the Gusuku period , like the other castles of Okinawa . When King Shō Hashi unified the three sections of Okinawa and established the Ryūkyū Kingdom , he used Shuri Castle as a residence . At the same time , Shuri flourished as the capital and continued to do so during the second Sho dynasty . For 450 years from the beginning of the 15th century , it was the royal court and administrative center of the Ryūkyūan Kingdom . It was the focal point of foreign trade , as well as the political , economic , and cultural heart of the Ryūkyūs . According to records , Shuri Castle was burned down several times , but rebuilt each time . Before World War II , it was designated a national treasure . However , during the war , the Japanese military set up its headquarters in the castle underground , and , beginning on May 25 , 1945 , the American battleship shelled it for three days . On May 27 , it burned . After the battle , a Confederate battle flag ( which personally belonged to the company commander ) was hoisted above the castle by the " Rebel Company " A of the 5th Marine Regiment . It was visible for over two miles and stayed above the castle for three days until it was removed by General Simon B . Buckner , Jr . ( son of Confederate General Simon Bolivar Buckner , Sr . ) , who stated that Americans from all parts of America helped to win the battle . After the war , the University of the Ryūkyūs moved to the castle site , where it remained until 1975 . In 1958 , the Shureimon gate was reconstructed and , in 1992 , the main building of the castle was reconstructed . At present , the entire area around the castle has been established as Shuri Castle Park . In 2000 , along with other gusuku and related sites , it was designated as a UNESCO World Heritage Site . Sites of interest . Because of its central role in Ryūkyūan political and religious life , Shuri Castle is surrounded by various sites of historical interest , including Shureimon , the main gate to the castle , and the Tamaudun Mauseoleum , the royal tombs located adjacent to Shuri Castle . Stone Gate of Sonohyan - utaki . This stone gate to the left of Shureimon gate was erected in 1519 by King Shō Shin , the third king of the second Shō dynasty . Here at the Sonohyan - utaki , the king offered prayer s for order throughout the kingdom and safety at the outset of all his travels . The stone gate reflects the kingdom ' s advanced limestone masonry skills . It is designated an important national cultural property , and is itself also registered as a distinct element of the collective UNESCO World Heritage site designated as " Gusuku Sites and Related Properties of the Kingdom of Ryukyu " , alongside Shuri Castle itself . Shikina - en . Built in 1799 , the royal gardens and villa were not only where the royals relaxed but was also used to host the investiture envoys who came from the Great Empire , China . The garden ' s circle layout resembles plans used in modern Japanese garden s , but the villa itself with its red tile is uniquely Ryūkyūan , and pond and bridge to the miniature island is in the Chinese style . This is a rare , historically valuable example of Ryūkyūan landscape gardening , and Shikina - en is also registered as a distinct element of the collective UNESCO World Heritage site designated as " Gusuku Sites and Related Properties of the Kingdom of Ryukyu " , alongside Shuri Castle itself . Kankaimon . First built around 1477 – 1500 during the reign of King Shō Shin , the gate was burned down during the Battle of Okinawa in 1945 and restored in 1974 . Kankaimon is the first front gate to Shuri Castle , " kankai " ( 歓会 ) , which means " welcome " . The gate was named to express welcome to the investiture envoys who visited Shuri Castle as representatives of the Chinese Emperor . " Bridge of Nations " Bell . The was cast in 1458 , during the reign of King Shō Taikyū , and hung at the Seiden ( main hall ) of the castle . The 721 kg bell is today in the collection of the Okinawa Prefectural Museum ; a full - size replica hangs on the castle site . The inscription on the bell describes Ryūkyū ' s prominence in maritime trade in the South Seas and prosperous trade relations with China , Korea , Japan , and the various states of Southeast Asia ; the bell ' s name derives from this . In Popular Culture . In , the last American mission ( " Breaking Point " ) takes place in Shuri Castle , where the U . S . Marines make their final push to take Okinawa . In , the last mission takes place assaulting Shuri Castle .