The Xiancantan (Chinese: 先蚕坛), known in English as Altar to the Goddess of Silkworms, is an imperial altar in Beijing, China, similar to the Imperial Ancestral Hall, Xiannongtan (Temple of Agriculture) and the Altar of Earth and Harvests. It is located at the eastern ground of the Beihai Park, a large imperial garden in the city's historical centre.