Hwaseong (Brilliant Castle/ Fortress), the wall surrounding the centre of Suwon, the provincial capital of Gyeonggi-do, South Korea, was built in the late 18th century by King Jeongjo of the Joseon Dynasty to honour and house the remains of his father Prince Sado, who had been murdered by being locked alive inside a rice chest by his own father King Yeongjo having failed to obey his command to commit suicide. Located 30 kilometres (19 mi) south of Seoul and enclosing much of central Suwon including King Jeongjo's palace Haenggung, UNESCO designated the fortress a World Heritage site in 1997. The Suwoncheon, the main stream in Suwon, flows through the centre of the fortress. Hwaseong Fortress was built over two and a half years, from 1794 to 1796 according to the designs of the architect Jeong Yak-yong, who would later become a renowned leader of the Silhak movement. Silhak, which means practical learning, encouraged the use of science and industry and Jeong incorporated fortress designs from China and Korea along with contemporary science into his plans. Use of brick as a building material for the fortress and employment of efficient pulleys and cranes were also due to the influence of Silhak. Construction of the fortress was also a response to the collapse of the Korean front line during Imjin war. At the time, the dominant model for building fortresses in Korea was to make a simple wall for the city or town and a separate mountain fortress to which the people could evacuate in times of war.