Vre­de­fort Dome, approx­i­mate­ly 120 km south-west of Johan­nes­burg, is a rep­re­sen­ta­tive part of a larg­er mete­orite impact struc­ture, or astrob­leme. Dat­ing back 2,023 mil­lion years, it is the old­est astrob­leme yet found on Earth. With a radius of 190 km, it is also the largest and the most deeply erod­ed. Vre­de­fort Dome bears wit­ness to the world‘s great­est known sin­gle ener­gy release event, which had dev­as­tat­ing glob­al effects includ­ing, accord­ing to some sci­en­tists, major evo­lu­tion­ary changes. It pro­vides crit­i­cal evi­dence of the Earth‘s geo­log­i­cal his­to­ry and is cru­cial to under­stand­ing of the evo­lu­tion of the plan­et. Despite the impor­tance of impact sites to the planet‘s his­to­ry, geo­log­i­cal activ­i­ty on the Earth‘s sur­face has led to the dis­ap­pear­ance of evi­dence from most of them, and Vre­de­fort is the only exam­ple to pro­vide a full geo­log­i­cal pro­file of an astrob­leme below the crater floor.