It is also the setting of the Joint Training Arc.
Ground Gamma consists of an industrial site compiled by many factories that form a labyrinth. The labyrinth contains tons of heavy machinery including cranes and pipelines.
Following Class 1-A's internships with the Pro Heroes, Ground Gamma was used by All Might for a basic hero training class. He had the students split into groups and race towards a distress beacon somewhere within the maze of machinery. The environment favored vertical movement, giving Hanta Sero the biggest advantage out of the first group of students.
Hanta believed that the field was made for his Quirk. However, Izuku Midoriya was able to challenge him for first place using his newfound abilities. Izuku ultimately failed after losing his footing that while moving in an area with unstable footholds, he must also pay attention to where he lands. Due to Izuku's mistake, Hanta Sero ends up winning the first race.
Ground Gamma was also one of the settings for the Final Exams at the end of Class 1-A's first term. The field was the battleground for Denki Kaminari and Mina Ashido's practical test against Principal Nezu. By occupying a crane and using his pristine knowledge, Nezu was able to knock down several metal structures on the grounds to impede any methods of escape for the students. He only leaves a single escape route for Denki and Mina, but they fail after being unable to outwit their Principal.
Ground Gamma was the setting for the Joint Training Battle, with all five rounds taking place there.