Hoàng Sa is an island district of Da Nang in the South Central Coast region of Vietnam. It covers an area of 305 km2 (118 sq mi) of the Paracel Islands, including these main features: Pattle Island, North Reef, Robert Island, Discovery Reef, Passu Keah, Triton Island, Tree Island, North Island, Middle Island, South Island, Woody Island, Lincoln Island, Duncan Island, Bombay Reef, Observation Bank, West Sand, Vuladdore Reef and Pyramid Rock.