Abyssal hills are small hills that rise from the abyssal plain, which is the floor of the ocean.
grand canyon
At the mouth of a submarine canyon, you would expect to find a submarine fan. This is a large accumulation of sediment that has been transported down the canyon and deposited on the ocean floor as the canyon widens and reaches the abyssal plain.
A coastal plain would border an ocean.
plain
plain
plain
In the Abyssal Ruins.
A coastal plain would border an ocean.
you can find a plain in Australia
To find oil....
The 4th floor in Abyssal Ruins. Map at marriland.com