Green Hill Zone (グリーンヒルゾーン Gurīn Hiru Zōn) is the first level of the 1991 Sega Genesis video game Sonic the Hedgehog. The level is grassy and lush, with environmental features such as palm trees, vertical loops, and cliffs, and is the home of numerous forest animals. Like the game's other levels, Green Hill comprises three acts; in the third, Sonic fights antagonist Doctor Eggman before moving to the second level, Marble Zone. It was constructed by level designer Hirokazu Yasuhara and its musical theme was created by Masato Nakamura.