Previous and recent geological, topographic, drilling, and geophysical data are summarized to acknowledge the 100 km original size of the relatively young and well-preserved multi-ring Popigai impact structure and to estimate the depth of its erosion. The relics of the bedrock rim are traced in the northern and western sectors of the crater, allowing the correct evaluation of the crater diameter. The depth of erosion varies in different crater sectors and concentric zones from 50 to 100 m to 300 m. The most significant erosion occurred on the crater rim. The crater rim has a complex inner structure and is...