Big O Area
Apparently you call the structure as the "Big O." And "O" stands for Ocean. The area itself is automatically the Big O Area...So what happens here? Well it's the place where you can see spectacular performances. During day time you could see a different and unique performances from foreign and local performers. I saw my long time Uzbekistan friend who's working as an interpreter for the performers so I assumed that the foreign performers must be from Russian speaking countries. The performance is really amazing. They've utilized the air, water and the whole Big O area too. I am not sure but I guess it's usually at 2pm. In the evening, the area transforms into a K-Pop concert venue or local performances from different performing groups.
During day time the Big O structure does not do anything but the water fountain beside it works hard. hehe. There's a water fountain show during day time which you can enjoy maybe after walking for a long time. In the evening the Big O transforms into something super cool, amazing and breathtaking. Together with the water fountain, it will be giving you a superb show ^^ I remember some Korean kids after the show saying, "It's worth a penny...even if we did not see the K-Pop concert and other pavilions...we're happy that we've seen the Big O show"
So it's really worth watching ^^ Anyway, my suggestion, do not sit right in front because you'll be wet and I think the best location is the bridge facing the Big O. It would give you good angles for pics and videos and your view will be perfect. Make sure you charge those batteries and empty some spaces for your memory card because it's really wonderfrul to watch and record for some expo souvenir ^^ Here are some video clips of the show