Exploring the Earth (Part 1)

While searching for Nobita’s coin, Doraemon and his friends encounter an underground city deep inside the Earth. They go underground and discover find an ancient city built more than 1400 years ago, as well as an empty treasure box inside a pyramid. To uncover what was inside that treasure box, the gang travel back in time 1400 years, but find the treasure box missing. Doraemon, Nobita and Gian are caught by the gatekeepers of the city of Pakal and sent to prison when the Gian ventures out of the underground city with Doraemon and Nobita persuading him to go back. Dorami, Shizuka and Suneo go out to find them in the adjacent city of Bokal.