Green Hill Zone

The Green Hill Zone was the first level in the original Sonic the Hedgehog game, as well as being used in many games after. It is an idyllic forest-like Zone set next to a lake, with features including palm trees, totem poles, rock formations in the shapes of loops and corkscrews, waterfalls, and distinctive striped grass with chequered soil.

The area has been used in Archie Comics' Sonic the Hedgehog series in both Sonic: Genesis, Worlds Collide and Worlds Unite, as well as in Sonic Universe & Mega Man.

The Green Hill Zone is also a level in Super Smash Bros. for Nintendo 3DS.

Sonic: Genesis
After Dr. Eggman launched the Genesis Wave, Sonic the Hedgehog found himself running through the Green Hill Zone, hoping to find his friends. While there, he encountered a group of Motobug, as well as a Newtron which took him to Snively Robotnik. Sonic defeated Snively, and destroyed several capsules in his possession, freeing Sally Acorn, Antoine & Rotor Walrus. (Sonic the Hedgehog #226)

Worlds Collide
After the Genesis Wave that was launched by Dr. Eggman and Dr. Wily, Sonic found himself looking for his friends (Miles "Tails" Prower, Amy Rose and Knuckles the Echidna) in the Zone, with a feeling of Déjà vu. (Sonic Universe #51)

At the same time, Mega Man in pursuit of the Roboticized Masters and Metal Sonic (who moves too fast for Mega Man to get a clear view), chase them from Mega City into the Green Hill Zone through a Warp Ring. Afterwards, Sonic runs into Silver the Hedgehog, who is shortly captured by Copy Robot. Sonic follows him, only to come across the real Mega Man, with the two of them fighting each other. (Mega Man #24 and Sonic Universe #51)

Both of them fight as hard as possible, though Sonic fares better than the Blue Bomber due to the layout of the Green Hill Zone. During the battle, Dr. Light managed to recreate the Warp Ring portal, allowing Mega Man to take the fight back to Mega City. (Sonic the Hedgehog #248)

Worlds Unite
Sonic arrives to the ruined Green Hill Zone through Tails' directions on a Chaos Emerald located there. He nearly falls off a cliff due to Green Hill Zone ending, but runs alongside the walls (also quipping that gravity "was only a theory anyway"). While further down the cliff, he saves a small bird and instead of a Chaos Emerald, finds a shard of the Master Emerald to retrieve for Knuckles.

Afterwards Sigma sends Zavok, Zeena and Zor of the Deadly Six to the location through a Genesis Portal to defeat and capture Sonic. (Sonic Universe #76)

Note

 * The beginning of Mega Water S's stage in Mega Man: The Wily Wars resembles the Green Hill Zone.