Port Lockroy has been a safe anchorage following its use by the whaling fleets of the early 20th century, and for this reason was selected for the first continuously occupied British base to establish a year-round British presence in Antarctica. Base A, Port Lockroy, was established on 11 February 1944 as part of a wartime mission code-named Operation Tabarin. Designated Historic Site and Monument no. 61, Port Lockroy, has been fully managed by UKAHT since 2006.

Built on Goudier Island in the west of Port Lockroy, Base A is situated in a sheltered harbour off the coast of Wiencke Island and at the meeting of three seaways which offer some of the most dramatic mountain and glacier scenery on the west side of the Antarctic Peninsula. For more than a century, Port Lockroy has been a home for explorers, whalers, scientists, and sailors who have made vital contributions to Antarctic history, and the harbour has become the most popular visitor destination in Antarctica today.