Horseshoe Island (Antarctica)

Horseshoe Island is a crescent-shaped island located in Marguerite Bay, off the west coast of Graham Land in Antarctica. It lies approximately 12 kilometers (7.5 miles) southwest of Pourquoi Pas Island. The island derives its name from its distinctive horseshoe shape.

During the period of 1955 to 1960, Horseshoe Island was the site of "Station Y" (also known as "Horseshoe Island Base"), a British Antarctic Survey (BAS) research station. The station primarily focused on surveying, geology, and glaciology in the surrounding area. A significant undertaking during this period was a comprehensive survey of Marguerite Bay, which produced detailed maps of the region.

After the base was closed in 1960, it remained largely untouched. In 1995, the site was designated Historic Site and Monument No. 63 under the Antarctic Treaty System. This designation recognizes the historical significance of Station Y as a well-preserved example of a British research station from the International Geophysical Year (IGY) period (1957-58). Visitors are permitted to view the site but are expected to adhere to strict guidelines designed to protect the station and its contents from disturbance. The station provides a unique glimpse into the living and working conditions of Antarctic researchers during the mid-20th century.