☆Location: Forbidden Valley
☆Manufacturer: B&M
☆Type: Inverted Coaster
☆Cost: £10 million
☆Max. Speed: Approx 81km/h
☆G-Force: 4G
☆Passengers per Car: 32
☆Capacity: 1400 riders per hour
☆Duration: 1 min 20 secs
☆Opening Year: 1994 (19th March)
Links to John Wardley's book on Nemesis and other attractions:

Nemesis Reborn is a steel inverted roller coaster located at Alton Towers at Alton Towers UK. Built by Bolliger & Mabillard, it opened in 1994 under the name Nemesis and was the first inverted roller coaster outside of North America. It is also the first B&M coaster outside of North America.
DEVELOPMENT
During the time when the Tussauds company owned Alton towers, In 1990, Thunder Looper roller coaster was added however this was only temporary as the tree line restriction, preventing anything being built taller than the highest tree, imposed on the park due to being a historic site caused the thunder looper to be a risky instalment. They desired a roller coaster that was exciting to draw crowds in without causing controversy and so they began thinking of solutions, deciding on tasking john Wardley, a developer for theme parks in the UK and Europe, the challenge.Before Nemesis was thought of John Wardley proposed the concept for a ride themed as a secret military weapon, codenamed "Secret Weapon", which would become synonymous with future first of their kind attractions. Due to the design of the ride and the height restriction imposed on the park, the Secret Weapon would only have a track length of 300 metres (980 ft). A year later, a revised layout was drawn up, dubbed "Secret Weapon 2". Rock blasting was used to excavate space for the planned ride. However, the Arrow pipeline project was cancelled when Wardley rode the prototype, describing how it was "very slow (and rather boring)" which took them back to the drawing board for Secret Weapon 3.Then Tussauds became aware of a new roller coaster model being built by B&M at Six Flags Great America and entered into discussions with Six Flags, who agreed to privately disclose information about the new ride. Jim Wintrode, the general manager of Six Flags Great America at the time, proposed the concept of an inverted roller coaster that featured inversions and worked with B&M to develop Batman: The Ride. Inspiring the idea for an Alton towers inverted coaster which would become the worlds first outside of North America. Wardley and Nick Varney, marketing director of Alton Towers, came up with the theme for "Nemesis" as an alien creature excavated from the ground. According to Wardley, the ride's name was conceived one evening after himself and Nick Varney drank a bottle of Southern Comfort.
OPERATION
The £10 million Nemesis officially opened to the public on 19 March 1994, billed as ‘The Most Intense Ride Experience’. The opening in 1994 of The Big One, Nemesis and Shockwave at Drayton Manor resulted in 1994 being celebrated by UK's parks and fans as the "Year of the Rollercoaster".
In August 2004, Nemesis gained the Guinness World Record for the "Most Naked People on a Rollercoaster". The ride set the record at 32 riders – the number of seats on a single Nemesis train. It took the record from Thorpe Park's Nemesis Inferno roller coaster which set the record at 28 just three months prior. The ride lost the record in 2010 when 40 naked riders boarded Green Scream Rollercoaster at Adventure Island.John Wardley once said: "The design and build of Nemesis stands as one of my undisputed career highlights. I don’t think anyone involved with the project could have predicted how much of a game-changer it would be and how it would be cherished by so many."
AREA
Originally known as Thunder Valley in 1990 when the Thunder Looper was installed, this was the only ride in the area until in 1992 when the New Beast was moved from Talbot Street to the bottom part of the area. 1994 saw the opening of Nemesis, Europe's first inverted coaster and the area was re-named to Forbidden Valley. In 1997 the Thunder Looper was removed and Ripsaw, a Top Spin flat ride was installed into the area along with a re-vamped pirate ship called The Blade. In 2002 the world's first B&M flying coaster was opened to the public named Air.