Expo 2012 has opened in South Korea's coastal city of Yeosu for a three-month run.

Organizers say the fair, which kicked off Saturday, has the largest number of robots in the history of expos. Attractions include a robot fish that explores underwater resources in an environment-friendly way.

Organizers say about 33,000 tickets were sold for the opening day. More than 100 countries are participating in the expo to display their technology, culture and products.

Yeosu is a port city 300 kilometers (185 miles) south of Seoul. It has built a gigantic structure in the water to display colorful hologram images and promote the expo.