Forbidden Valley is situated at the back of the park, behind Gloomy Wood. It is one of most popular areas of the park for thrill seekers, with the ride line-up geared towards an adrenaline rush and certainly not the faint-hearted. Forbidden Valley has been said to be one of the best themed areas in the park, themed around 'Nemesis', the monster. The story behind the area is that when work was being carried out, diggers heard a very loud, strange noise. This was the movement of a huge underground monster. The workmen's only chance of survival was to capture or stop the monster, they built a massive turning and twisting track which still lays there today, keeping Nemesis trains under control. To continue the theme, Ripsaw is themed as a piece of shrapnel that came flying out of the hole when Nemesis was discovered.

On the other side of Forbidden is AIR, the world's first flying rollercoaster, added to the area in 2002. AIR (Aerial Inversion Ride) is a light aqua blue colour and doesn't continue the monster theme, but is themed around flight.

History of Forbidden Valley

Forbidden Valley originally started out at Alton Towers as Thunder Valley in 1990 when the Thunder Looper was installed, this was the only ride in the area until the addition of the New Beast in 1992 which was moved from Talbot Street (Now Cred Street) to the lower end of Thunder Valley (To where Nemesis now stands). The Beastie (Now in Adventureland) was also installed as a children's coaster so Forbidden Valley appealed to the whole family.

By 1993 Thunder Valley was one of the most popular areas in the park. In 1994 Nemesis was opened and the area received a name change to Forbidden Valley. Eventually in 1997, after 7 extremely popular years Thunder Looper was removed due to the new height and ride sound restrictions put on the park. Forbidden Valley got two new thrill rides to replace the Thunder Looper, Blade, which was the old Pirate Ship from Fantasy World (Now X Sector) and Ripsaw, a brand new Modial Top Spin.