Tabun-Khara-Obo is an impact crater in the Dornogovi Aimag (province) the south-east of Mongolia. The crater, which is exposed at the surface, is 1.3 km in diameter. The crater's rim rises some 20 to 30 meters above the crater bottom, but the bottom of crater is covered with up to 171 m thick layer of lake deposits - a testimony that this crater in earlier times was filled with a lake. It has an estimated age of 150 ± 20 million years (Upper Jurassic). The site was first identified as a probable impact crater in the 1960s, although confirmation of the hypothesis only occurred decades later.