Dragon Ball Z S01E15 - Dueling Piccolos

Escape from Piccolo! Gohan Summons a Storm

When Goku had finally traveled halfway, Gohan, who was training in the wilderness, became homesick and tried to go back home. However, no matter how much he ran along the coast after passing through the desert, he always ended up back where he started. Curious, Gohan climbed a mountain and discovered that he was on an island.