A crater or walled plain lying in a field of such structures on the edge of Oceanus Procellarum, the Ocean of Storms on the Moon. Hevelius is circular in form with a diameter of some 106 km, but lies so close to the western limb of the Moon's visible face that it appears as a long foreshortened ellipse as seen from Earth.
To the immediate north of Hevelius, so close that their rims connect with one another, is a smaller structure of the same kind known as Cavalerius. To the west is an even larger walled plain, Hedin, while to the south are two others designated Riccioli and Grimaldi.
The floor of Hevelius was formed by lava flooding the crater, and lies some 1.8 km below the highest parts of its raised rim (some parts of the rim walls are now heavily eroded, especially in the southwest). The floor of Hevelius is speckled with small craters, as well as two larger 14-kilometre craters, one of which intersects the decayed southwestern wall. The floor also shows a number of straight rilles, the Rimae Hevelius, two of which run across each other to form a cross shape, with one arm of the cross running across Hevelius' southeastern wall and out onto the plains beyond.