The "Northern Sea" is actually the world's deepest (at up to 1940 meters) and most ancient freshwater lake. When the wind blows, the powerful waves on the lake are like those seen in the ocean.
「北海」，實際上是世界最深（可達 1940 公尺）、年代最古老的淡水湖，風起時波瀾壯觀，不下於汪洋大海。