The music festival has taken place in the Netherlands as part of an experiment relating to the spread of COVID-19.

Around 1,500 people have been able to go to a music festival in the Netherlands as part of a Covid-19 science experiment.
All attendees were tested for the virus before entering, and if they tested negative they were allowed to behave as if they were at an event before the pandemic.
Their movements were tracked during the event, in an effort to find out more about the potential spread of COVID, and then they were tested again afterwards.
Microbiologist Andreas Voss is one of the scientists behind the experiment, and has said it's vital that people behaved normally during it.
"We want to have the way they party usually, because otherwise all the data we would have would be senseless."
Return of gigs
It's not yet clear when live music events will be able to happen safely here, as we wait to find out what changes will be made to restrictions from April 5th.
Organisers of Electric Picnic recently said they hoped the vaccination rollout would allow for the festival to go ahead this year, but they could not give any confirmation at this stage.
3/ The Electric Picnic team remain hopeful that the vaccination roll out will be complete in sufficient time to allow the festival to go ahead obviously but remain in Government hands for that.
— Electric Picnic (@EPfestival) March 8, 2021
They had been responding to claims made in a newspaper article, which they said were not the views of any of the organising team.
In the UK, plans are continuing for the Reading and Leeds music festivals, after last month's announcement that they will go ahead this year.
They are due to take place from August 27th to 29th.