Skull Valley is a location just outside of Mount Paozu which was seen in the second episode of Dragon Ball, "The Emperor's Quest" and in Chapter 2 of the Manga. Goku and Bulma camp out there for the night on the first day of their journey to collect the Dragon Balls. The land is very normal but another part of it is a canyon full of bones and populated with carnivorous wolves. Emperor Pilaf's minions Shu and Mai investigated a glow coming from the valley thinking it was a Dragon Ball.
Umigame was also found around here by Goku and Bulma to take to the beach. In episode 3 the place was shown again in a small scene of Bulma taking the Capsule House back with her to continue the journey.
In the Credits scene for most of Dragon Ball, Skull Valley is shown along with the capsule house on a rainy night with Bulma looking out the window in her night gown.The scenes of the wolves and Bones are only part of the Anime and are not seen in the Manga. The name Skull Valley was not mentioned in the manga either.