The rave started on the May Bank Holiday weekend in 1992.
It was publicised through a recorded message on an answerphone.
Many New Age Travellers came to the event, following the cancellation of another festival in the West Country.
An estimated 40,000 people were at the rave, setting up a massive campsite on the common land in the shadow of the Malvern Hills.
There were as many as five different sound systems at the rave - the music could be heard in Malvern.
It was a week before the last campers left the site.
Some of the sound systems were confiscated by the Police, and there were a number of court cases following the rave.
The Criminal Justice and Public Order Act 1994 was passed after the rave, to stop any more large scale illegal festivals.
The Criminal Justice and Public Order Act 1994.
This was a bigger Act of Parliament, controversial at the time because of changes to a person's right to silence, which also included legislation to stop illegal raves.
The Act gave the Police powers to stop and break up a "gathering on land in the open air of 100 or more persons (whether or not trespassers) at which amplified music is played during the night".
The Act singled out "music (that) includes sounds wholly or predominantly characterised by the emission of a succession of repetitive beats".
It gave the Police powers to stop people travelling to an event, and to seize and remove vehicles and sound systems.