Big O is a centerless Ferris wheel at Tokyo Dome City that looks down on Tokyo Dome. Some gondolas have karaoke machines, and riders can sing designated songs, including Korean ones, while viewing Skytree and the Tokyo Dome City scenery. One ride takes about 15 minutes, and tickets are bought on site from a vending machine across from the entrance. The gondolas have air conditioning, and the number of karaoke songs is not large.