What is the largest corona on Venus?

The largest corona on Venus is Artemis Corona.

Artemis Corona lies in Aphrodite Terra, one of Venus’s major highland regions, and measures about 2,600 kilometers across. It is associated with the near-circular Artemis Chasma, a huge belt of curved ridges and troughs.

A corona is a large, roughly circular or oval geological structure marked by concentric fractures and volcanic or tectonic features. Scientists think Venusian coronae may form when hot mantle material rises, pushes the crust upward, and then spreads or collapses as magma moves outward.

Artemis is unusual because it is not simply a raised mountain-like feature: parts of its interior lie below the surrounding plains. Its complex combination of fractures, rifts and compressional arcs has led some researchers to compare it with a possible regional form of tectonic activity. It is easy to confuse the answer with Heng-o Corona, another large feature, but Heng-o is substantially smaller, at about 1,060 kilometers across.