The Horseshoe Island is up to 10 kilometres long and 6 km wide. It is situated in the Marguerite Bay in the west of Adelaide Island. On the Horseshoe Island a british base was opened on March 1955, known as Base Y. It closed 1960 and later it has been designated as a historic site by the secretary of the Antarctic Treaty.
The highest point on the island is the Mt. Breaker (878 m) in the southern part. Other summits are known as Ryan Peak, Trifid Peak and Mt. Searle (537 m).
British Antarctic Territory 2003, Base Y at Marguerite Bay on Horseshoe Island.
The mountain in the background is Mt. Searle (537 m).
The stamp was issued in the bases and postmarks series 2003.
British Antarctic Territory 2003, Base Y.
The stamp was issued in the series "British Historic Huts".