Sandy's Island is an island that Sandy was stranded on after being hit by a giant wave in the episode, SpongeBob SquarePants vs. The Big One. For survival, Sandy made many innovations (see list). The island is also home to Dennis. The island has three volcanoes on it and much vegetation.
Before Sandy's adaptations, the island was very vast and bleak. However, the island is revealed to bear many valuable and life-preserving resources, such as vegetation for food and other useful resources. Several palm trees and three volcanoes are spotted on the island. No other wildlife other than Sandy and an elderly Dennis are spotted on the island.
Sandy's adaptations to the island change the terrain slightly, yet make the appearance much different. The adaptations use the free space the island does not use and take advantage of its resources. The appearance changes, yet the island itself is not truly affected.