Castle Mountain () is a mountain located within Banff National Park in the Canadian Rockies, approximately halfway between Banff and Lake Louise. It is the easternmost mountain of the Main Ranges in the Bow Valley and sits astride the Castle Mountain Fault which has thrust older sedimentary and metamorphic rocks forming the upper part of the mountain over the younger rocks forming its base. The mountain's castellated, or castle-like, appearance is a result of erosive processes acting at different rates on the peak's alternating layers of softer shale and harder limestone, dolomite and quartzite. The mountain was named in 1858 by James Hector for its castle-like appearance. From 1946 to 1979 it was known as Mount Eisenhower in honour of the World War II general Dwight D. Eisenhower. Public pressure caused its original name to be restored, but a pinnacle on the southeastern side of the mountain was named Eisenhower Tower. Located nearby are the remains of Silver City, a 19th-century mining settlement, and the Castle Mountain Internment Camp in which persons deemed enemy aliens and suspected enemy sympathizers were confined during World War I. While looking nearly inaccessible from the Trans-Canada Highway, the peak can be ascended from the backside on the northeastern slopes. The trail to Rockbound Lake leads hikers around the eastern side. The massif contains several high points including Helena Ridge (), Stuart Knob () and Television Peak (), the latter being named for the TV repeater located on top. Technicians use a helicopter rather than hiking the long ascent to the top. Geology Castle Mountain is the easternmost member of the Main Ranges in the Bow Valley. Passing through the mountain is the Castle Mountain Fault, a thrust fault which separates it and the other nearby peaks of the Main Ranges from the Sawback Range to the northeast, the westernmost of the Front Ranges in the region. Castle Mountain's upper sections, including its cliff faces, consist of late Pre-Cambrian and Cambrian age sedimentary rocks such as limestone and shale along with some metamorphic quartzite. Originally deposited in an ancient shallow sea, these deposits were later thrust over younger layers of late Paleozoic and Mesozoic age which now form the forested, gently sloping, base of Castle Mountain. It is an example of a castellated mountain in which erosion has sculpted a series of flat or gently sloping terraces composed of softer shale and sharp cliffs which