Doraemon Movie 37: Nobita no Nankyoku Kachikochi Daibouken

Trying to escape a scorching summer, Nobita and his friends use Doraemon's gadgets to build an amusement park on a drifting iceberg. There they discover a mysterious golden ring buried deep in the ice, and its age points to Antarctica thousands of years before any human should have left such an object there.

The search carries the group beneath the frozen continent and even across time, where they meet Carla and learn of an ancient crisis connected to a civilization lost in the ice. What began as a cool summer getaway becomes a race to stop a disaster capable of freezing the entire Earth.