No trip to Seoul would be complete without a visit to Lotte World Aquarium located in the basement of Lotte World Tower and Mall. It is a huge aquarium displaying more than 55,000 fish and more than 650 different species of marine creatures, making it one of the largest marine life exhibitions in Seoul. South Korea, where you can see penguins, jellyfish, otters, beluga whales, stingrays, sea lions and much more!