Forbidden Valley is a valley

Valley

In geology, a valley or dale is a depression with predominant extent in one direction. A very deep river valley may be called a canyon or gorge.The terms U-shaped and V-shaped are descriptive terms of geography to characterize the form of valleys...

 to the south of Citadel Peak

Citadel Peak

Citadel Peak is located on the border of Alberta and British Columbia on the Continental Divide. It was named in 1913 by Arthur O. Wheeler.-See also:*List of peaks on the British Columbia-Alberta border*Mountains of Alberta*Mountains of British Columbia...

 in Hays Mountains

Hays Mountains

Hays Mountains is a large group of mountains of the Queen Maud Mountains, surmounting the divide between the lower portions of Amundsen and Scott Glaciers and extending from the vicinity of Mount Thorne on the northwest to Mount Dietz on the southeast. Discovered by R...

. The valley drains east-northeast from Mount Crockett

Mount Crockett

Mount Crockett is a prominent peak, 3,470 m, standing 2 nautical miles east of Mount Astor in the Hays Mountains of the Queen Maud Mountains. Discovered by members of the geological party under Laurence Gould during the Byrd Antarctic Expedition, 1928–30, and named by Byrd for Frederick...

 to Scott Glacier

Scott Glacier (Transantarctic Mountains)

The Scott Glacier is a major glacier, 120 miles long, that drains the East Antarctic Ice Sheet through the Queen Maud Mountains to the Ross Ice Shelf...

 and is partly covered by glacier

Glacier

A glacier is a large persistent body of ice that forms where the accumulation of snow exceeds its ablation over many years, often centuries. At least 0.1 km² in area and 50 m thick, but often much larger, a glacier slowly deforms and flows due to stresses induced by its weight...

 and moraine. It was visited in December 1987 by a United States Antarctic Research Program (USARP)-Arizona State University

Arizona State University

Arizona State University is a public research university located in the Phoenix Metropolitan Area of the State of Arizona...

 geological party led by Edmund Stump. The mouth of the valley is blocked by a moraine which denies easy access, hence the name.