Developers want to give millions of visitors the 21st century's best "white knuckle" rides in the pounds 500 million park planned for 800 acres of farmland near the M4 in south Wales. It would also be the world's first all-weather theme park, with much of it covered by a huge hi-tech membrane.
A Bristol-based consortium, Legend Court Ltd, revealed their plan at a golf club near the proposed site at Magor, just a minute's drive from the new Severn bridge.
A detailed planning application will be submitted to Newport and Monmouthshire County Borough Councils next month. If approved, the park would open in summer 2001 for an estimated 2.7 million visitors a year.
Councillors are concerned about the impact of such a huge development on nearby villages. But the developers promised it would be "environmentally friendly", and said there would be full consultation.
A public inquiry on the massive scheme is expected, possibly next year, with the final decision being taken by Welsh Secretary Ron Davies.