It is The Marianas trench it is the deepest underwater canyon and i believe the longest at 1580 miles.The mid atlantic ridge stretches 10,000 miles!
Hells canyon.
The Great Canyon of Yarlung Tsangpo River, located in Tibet is the largest canyon on Earth, but the largest known canyon is Valles Marineris, located on Mars.
I believe it is the Mariana Trench, about 7 mi deep, off the coast of Taiwan
The Yarlung Zangbo Canyon is in Tibet.
Grand Canyon.
canada
siberia
Horizons
greenland
The worlds largest bony fish is the Actinoptergyii.
Avenida 9 de Julio is the worlds LARGEST road. Only LARGEST. not WIDEST. Avenida 9 de Julio is the worlds LARGEST road. Only LARGEST. not WIDEST.
An ancient under sea valley carved in the ocean floor is known as a canyon, usually given the name of the contributory river on the land. such as the Hudson Canyon, or the Clutha Canyon.