Heksagon Tarn (Bulgarian: езеро Хексагона, romanized: ezero Heksagona, IPA: ['ɛzɛro hɛksɐ'gɔnɐ]) is the lake on the northwest coast of South Bay, Livingston Island in the South Shetland Islands, Antarctica extending 140 m in west–east direction and 100 m in south–north direction. It has a surface area of 1.04 ha and is situated 130 m from the sea. The area was visited by early 19th century sealers.[1]
The feature is so named because of its supposed hexagon shape ('heksagon' in Bulgarian).