[1] The plateau is largely bounded by steep cliffs that represent the rims of several major impact basins: Postumia to the north, Feralia to the east, Rheasilvia to the southeast, and Veneneia to the southwest.

Vestalia Terra is a large, roughly pentagonal plateau ~365 by ~180 km, with an estimated surface area of approximately 80,000 square kilometers.

[14][2]: 95, 99  As Vestalia Terra predates Divalia Fossae and all of its bordering basins suggests that it is an ancient feature, probably one of the oldest identified on Vesta.

[2]: 100  Compositionally, most of Vestalia Terra's surface is rather uniform, dominated by howardite—a mixture of diogenite and eucrite with large amounts of orthopyroxene and olivine[15]: 31 —with a few outliers.

Analysis from Dawn's VIR instrument shows that the dark material is compositionally similar to most of Vestalia Terra, albeit with finer particles, suggesting that the materia is in fact a massive ejecta streak from Drusilla.

Brumalia Tholus likely represents a magmatic laccolith, where intruding magma from a dike does not erupt but still has enough pressure to dome the surface upwards.