Alton Towers has announced that it will be launching the ultimate rollercoaster Thirteen on 20th March 2010.

Until now, Thirteen has been kept top secret under the name "Secret Weapon 6” and is the subject of much speculation from fans. The new £15m ride is billed to be the scariest in the UK and will join a long line of world first attractions at Alton Towers including "Nemesis", "Oblivion" and "Air".

New for 2010: Thirteen Thirteen will be based on the discovery of an unearthed ancient burial site in an area of unexplored woodland known as the Dark Forest. Built on the site of the old Corkscrew rollercoaster, visitors will be invited to take a petrifying ride on Thirteen, venturing into the seemingly living and breathing Dark Forest. There they will face an unknown horror that has been unleashed from the ancient crypt.

The ride has been developed with the world's leading coaster and thrill consultants who have collaborated to combine the ultimate elements of physical and psychological fear - to create what experts are dubbing a ‘psychoaster’.

John Wardley, rollercoaster expert said:

This ground-breaking technology is something never seen before and will open up a whole new concept for theme park rides. By combining physical and psychological terror, Thirteen will be the first ride to play on emotional fear and something coaster fans will not be prepared for.

We're thrilled to announce the launch of Thirteen at Alton Towers. This new ride will be a shocking, never-experienced-before rollercoaster and we’re excited that once again Alton Towers is able to offer visitors the chance to experience something unavailable in any other part of the world. However, just as we take physical health and safety very seriously, Thirteen demands that we also consider our visitors’ emotional health, and as such we’re not afraid of introducing necessary measures to ensure riders are fully prepared and healthy enough to brave Thirteen.