Built in 1969 at a cost of approximately US$2.5 million, Namsam tower was opened to the public in 1980. Seoul Tower was completed on December 3, 1971, designed by architects at Jangjongryul though at the time the facility interior was not furnished. It took until August 1975 for the third floor of the observatory deck, museum, open hall, souvenir shop, in addition to bring the other facilities to completion. However, despite finalization of tower construction, the observatory was closed to the public until October 15, 1980. Since then, the tower has been a landmark of Seoul. Tower elevation ranges from at the base to above sea level. Seoul Tower had its name changed to N Seoul Tower in 2005 whereas the N stands for 'new', 'Namsan', and 'nature.' Approximately 15 billion KRW was spent in renovating and remodeling the tower.