Rusokastro Rock is a twin rock at the north entrance to McFarlane Strait in the South Shetland Islands, Antarctica extending 170 m (560 ft) in northwest–southeast direction and 70 m (230 ft) wide, with its two parts separated by a 30 m (98 ft) wide passage. It is situated 1.6 km (0.99 mi) northeast of Pyramid Island, 5.7 km (3.54 mi) northeast of Williams Point on Livingston Island, and 5.7 km (3.54 mi) northwest of Duff Point on Greenwich Island. The area was visited by early 19th century sealers.