Natural
The Colorado river
Most likely it is the Gila (hee-ya) river
Grand Canyon, in Arizona
The Colorado River forms the west boundary of Arizona with California and Nevada.
The Sierra Nevada
The Chesapeake Bay.
The border between Mexico and Texas is the Rio Grande River, also known as the Rio Bravo. The border between Arizona and the Mexican state of Baja California is the Colorado River (Rio Colorado), which also flows through the Grand Canyon and the Hoover Dam. The rest of the border between the United States of America and Mexico is made up of arbitrary straight lines, not corresponding to any natural feature.
The Gulf of Mexico is a natural feature, located between the United States, Mexico and the island of Cuba.
natural feature of asia
Andes Mountains.
Natural