Lying deep below the Pacific Ocean, about 200 miles (322 kilometers) south of the island of Guam, is the Marianas Trench (also known as the Mariana Trench), which is 1,554 miles (2,550 kilometers) long and 44 miles (71 kilometers) wide. The deepest point of the Marianas Trench is 36,198 feet (11,033 meters). In the Atlantic Ocean, the Puerto Rico Trench is 28,374 feet (8,648 meters) below the surface. In the Arctic Ocean, the Eurasia Basin is 17,881 feet (5,450 meters) deep. The Java Trench in the Indian Ocean is 23,376 feet (7,125 meters) deep. Another deep point of note in the Pacific Ocean is Monterey Canyon off the coast of northern California. It is about 95 miles (153 kilometers) long and 11,800 feet (3,600 meters) deep. The cold waters generated in the trench create a perfect environment rich in foods that support a diverse range of wildlife.

In comparison to all of these ocean canyons, the most famous land canyon—the Grand Canyon in Arizona—is 277 miles (446 kilometers) long and 6,000 feet (1,829 meters) deep. The world’s ocean canyons are much more impressive, but most people will never see them.