There is no island at 58 degrees south and 27 degrees west. This point is 25 miles southwest of Saunders Island, which is part of the South Sandwich Islands. The 58th parallel south never crosses land, only ocean.
The South Sandwich Islands were discovered in 1775 by James Cook, who chose to name them after John Montagu, the 4th Earl of Sandwich. The islands were formed by volcanoes, some of which are still active. Saunders Island is home to Mount Michael, a volcano that most recently erupted in 2005. The South Sandwich Islands have been under British control since 1908, although Argentina challenged that sovereignty by claiming them in 1938. The Falklands War of 1982 was a result of this dispute.