Marble Zone (Adventures of Sonic the Hedgehog)

The Marble Zone is a location that appears in the Adventures of Sonic the Hedgehog. It is an area of Mobius filled with geysers and a rich mining underground.

Description
On the surface, Marble Zone is a barren and yellow rock-like expanse filled with active volcano-like geysers, a few cliffs and purple rock formations in the horizon. The underground of the Marble Zone contains an elaborate cavern system and is rich with precious metals and gemstones, such as gold, jewels and diamondius, making it perfect for mining.

History
At some point, Spelunk set up a claim in the Marble Zone and isolated himself in the area's underground cavers where he for years would mine for jewels and gold and managed to build up an immense treasure. To safeguard his treasure, Spelunk booby-trapped every tunnel in the Marble Zone.

In the present day, Sonic the Hedgehog and Tails were passing through the Marble Zone when they were pursued by Scratch and Grounder. When the Badniks had them cornered, Sonic and Tails escaped them by fleeing into a geyser from where they entered the Marble Zone's cavern system. While Scratch and Grounder pursued them into the caverns, they soon after lost track of Sonic and Tails. While running through the tunnels, Sonic and Tails stumbled upon Spelunk's collective treasure. However, Spelunk did not take kindly to this as he believed Sonic and Tails were after his treasure and wanted to tell others about it. Though Sonic attempted to tell Spelunk they just wanted to get out, the mole did not believe him and tried to dispose of them. Sonic and Tails tried to escape Spelunk in the tunnel and escape to the surface, but Spelunk managed to trap them in a diamondius cage.

Meanwhile, Scratch and Grounder, having discovered Sonic's location and Spelunk's treasure cave, returned to the surface of the Marble Zone with Dr. Robotnik to dig up Spelunk's cave and both claim his treasure and capture Sonic. As the evil trio began breaking into Spelunk's treasure cave, the place began coming down on them, freeing Sonic and Tails in the process. Sonic then saved Spelunk before he could be crushed a boulder and Spelunk realized Sonic and Tails were good enough. The three of them then banded together to escape Spelunk's collapsing, bobby-trap ridden tunnels and get to the surface where Robotnik and his Badniks were taking Spelunk's treasure. Sonic and Spelunk then worked together to defeat Robotnik and his Badniks and get the stolen treasure back. Having a change of heart, Spelunk then promised Sonic and Tails to leave the Marble Zone and use his treasure to help people.