The city of Yeosu consists of the Yeosu peninsula as well as 317 islands (49 inhabited, 268 uninhabited). Being midway along southern coast of South Korea, it is flanked by Namhae County in South Gyeongsang Province to the east with natural waterway, and the Bay of Suncheon to the west and northwest, the city of Suncheon sprawling along its banks. The city has three different City Halls. On 1 April 1998, the cities of Yeosu and Yeocheon, along with Yeocheon County merged to form the unified city of Yeosu.
Thanks to the sea wind and warm current, Yeosu has cool summers and mild winters. Its ocean climate also brings Yeosu relatively longer springs and autumns than other regions. Yeosu is a city of history and loyalty where the headquarters of South Jeolla Province Navy Base was located, and the Great Admiral Yi Sun Shin invented the Geobukseon (turtle ship) to save the country while serving as the Navy Commander.
Due to its appeal as an international ocean resort and tourist city, as well as its close proximity to the Yeocheon Industrial Complex, Yeosu has seen much development during the past several decades. In the 142nd General Assembly of BIE, held in Paris on 26 November 2007, the global community selected Yeosu as the host city for the 2012 World Expo. This Expo will be Korea's second, following Daejeon's 1993 Fair.