Great Moblin's Keep

In The Legend of Zelda: Oracle of Ages and The Legend of Zelda: Oracle of Seasons, you can find a Moblin Keep. This is basically a small cave-like area inhabited by Moblins. Upon getting to the end, you must defeat the Great Moblin in a boss battle. In Oracle of Seasons, walking by without entering causes the Great Moblin to start firing large bombs at you.