From Dragon Ball Encyclopedia, the ''Dragon Ball'' wiki
Yunzabit Highlands (ユンザビット 高地, Yunzabitto Kōchi; FUNimation "Yunzabit Heights") is a region on Planet Earth.
Bulma said that Yunzabit Highlands was at "the ends of the earth". The climate was very cloudy and cold. The area had strong winds and was very barren.
Yunzabit Heights was where the Nameless Namekian had landed on Planet Earth. His homeworld, Planet Namek, had been in danger of being destroyed and therefore his father had sent him to Planet Earth in a Namekian Spaceship. Kami told Mister Popo his story one hundred years ago. He said that he could not remember anything prior to living in Yunzabit Heights. The only thing he had was a letter that said to wait there for his family. He lived in his house, which he later found out was actually a spaceship, for an unknown number of years. Food was scarce and the letter had not said how long to wait, therefore he finally left the area. He returned to the area now and then, but he did not see any change. The spaceship was still there when Popo took Bulma Brief to the area. She took it to her father, Dr. Brief, and he fixed it up for space travel. Bulma, Kuririn, and Son Gohan then used it to get to Planet Namek.
Yunzabit Highlands was a location visited during the Z Warriors' search for the Dragon Balls in Dragon Ball Z: Attack of the Saiyans. During their visit, they were attacked by remnants of the Red Ribbon Army. They fought and defeated a Red Ribbon Army member using the RR Power Robot.
On a side note, the Nameless Namekian's Spaceship can be found on a hill here. Piccolo will react if the player investigates it. His reaction is little more than silence (though this is a typical reaction from Piccolo).