What is the name of the broad Martian basin that contains Hellas Planitia?

The Hellas impact basin is the broad Martian basin that contains Hellas Planitia.

Hellas is one of the largest and most recognizable impact structures in the Solar System. It formed when a large body struck Mars early in the planet’s history, excavating a vast depression in the southern highlands. The basin’s floor is now called Hellas Planitia, a name meaning the plain of Hellas.

The basin is roughly 2,300 kilometres across, although estimates vary depending on how its rim is defined. Its floor lies several kilometres below the surrounding terrain, making it the lowest major topographic depression on Mars.

Hellas Planitia can collect dust and atmospheric material, and its great depth produces higher atmospheric pressure at the surface than in many other Martian regions. It is sometimes mistakenly called a crater, but its enormous size and complex structure make impact basin the more precise term.