Cornice Cave is the eighth of the twelve levels featured in Jewelry Land of Yoshi's Safari. It is located in a mountain in the eastern part of the Dark Realm. After Bowser stole the twelve treasured gems of the land, he hit one of them in Cornice Cave. In their quest to reclaim the stolen gems and rescue Jewelry Land's rulers, Mario and Yoshi have to fight their way through the cave and defeat the Magikoopa who guards the gem.
The level itself is set in a vast cave area with rocks outlining the cave walls in the background. While traveling along the path winding through the cave, Mario and Yoshi mainly encounter green Koopa Paratroopas and Podoboos that try to impede their progress. In later parts of the level, green Warp Pipes can be seen sticking out of the ground. These pipes cannot be used, however, some of them contain Monty Moles that will hop out and attack once the player approaches the pipes. Halfway through the level, a blue Fire Snake appears which needs to be disposed of before Mario can continue his mission. Aside from the enemies, this level also features environmental obstacles in form of two lakes that need to be jumped over.
 Boss Fight: Magikoopa
After Mario and Yoshi reach the end of the track, they meet up with a Magikoopa who is the guardian Bowser entrusted the eighth gem of Jewelry land with. The battle against him takes place in two phases that are very similar, though. In both phases, the Magikoopa will teleport around on the screen. When left unhit for a while, he starts firing magical blasts at the player. The blasts can be blocked either by firing at them several times, or by attacking the Magikoopa before he can finish his attack. After being hit enough times in phase one, the boss switches over to phase two. The only difference between those phases is that in phase two, the Magikoopa is larger and also a bit quicker than before. After he took enough hits, the Magikoopa explodes and Mario and Yoshi are rewarded with the stolen gem.