Dralh Sea!
One of the unique terrains on Sumatra Continent that was ink-black during the day, resembling tar. With an extreme amount of salt and other heavy minerals dissolved into it, the Dralh Sea's water was the densest on the continent.
It was so dense that drowning in it was virtually impossible for a human or any low-density creature. During the day, the water absorbs the sunlight and becomes boiling hot, too dangerous for anyone to touch it, not to mention swim in it.
Contrastingly, the night was the exact opposite. Not only did it cool down in a matter of minutes after nightfall, it became freezing cold, often having small glacier sheets forming on it. Moreover, the sea glowed during the night.
