Expo '98 (1998 Lisbon World Exposition) was an official specialised World's Fair held in Lisbon, Portugal from Friday, 22 May to Wednesday, 30 September 1998. The theme of the fair was "The Oceans, a Heritage for the Future," chosen in part to commemorate 500 years of Portuguese discoveries. The Expo received around 11 million visitors in 132 days, while 155 countries and organizations were represented.