The Flying Windmill Island is seen in the "Feel Good Inc." video and "El Mañana" video. Noodle is seen riding it and playing her acoustic guitar. It was stated to be "the last place where the greatest guitar player was, before death" by Murdoc Niccals.
There are many stories of why the windmill island was made. It started in a Rolling Stone article that Mr. Kyuzo, Noodle's mentor and creator, was caught sending Noodle to Kong Studios and was told by his bosses that if he didn't kill her then they would kill him (see the article on Noodle to see why he sent her to Kong Studios). So, to save his life, he met with the Gorillaz and told them that Noodle should be on a Flying Windmill Island for the "Feel Good Inc." video. They agreed and so she was put there. This was the start of his plan. He gave another idea to put helicopters to shoot the windmill island down, but Murdoc rejected the idea. Soon, when the band needed an idea for the "El Mañana" video, Mr. Kyuzo stepped up and gave the idea to make Noodle look like she died in a crash, and Murdoc took the idea. He also took Kyuzo's idea for the pirate helicopters. Kyuzo told Murdoc that she will need a parachute to jump off at the end to survive. When Noodle put down the parachute in her room to get ready for the video, Kyuzo snuck in and rigged the parachute to back-fire. Somehow she actually survived by jumping off and got a big bruise on her eye, which she uses a mask to cover in Phase III.
The Effect on The Band
In the song "Feel Good Inc." by Gorillaz, it sings "Windmill Windmill, For the land, Turn forever, Hand in Hand", which was an added lyric because the windmill island was featured in the video, and it was not included in the original lyrics. The incident from the "El Manaña" video took a huge toll on the band, because they lost their lead guitarist, Noodle. It also made Noodle want to seek revenge on Murdoc and Mr. Kyuzo.
Damon Albarn also stated that it effected their music (less Guitar and more piano and Synthesizer).