Castor is a 6,221-foot-elevation (1,896-meter) summit located in the Grand Canyon, in Coconino County of northern Arizona, United States.

Topographic relief is significant as Castor Temple rises over 3,800 feet (1,200 meters) above the Colorado River in two miles.

[5] Clarence Dutton began the tradition of naming geographical features in the Grand Canyon after mythological deities.

[7] Access to this feature is via the Tonto Trail, and the first ascent of the summit was made April 19, 1971, by Donald Davis and Alan Doty.

Below is conspicuous, cream-colored, cliff-former Coconino Sandstone, which is the third-youngest of the strata in the Grand Canyon, and was deposited 265 million years ago as sand dunes.