Mud is often a feature of festivals. This year it became too much at one German event.

A heavy metal festival in Germany has been forced to halt admissions after heavy rain turned the site into a mud bath.

The Wacken Open Air festival is an annual event which takes place in fields outside the village of Wacken in northern Germany, attracting tens of thousands of heavy metal music-lovers.

This year, however, incessant rain turned the farmland into a muddy swamp, presenting severe accessibility problems and forcing organizers to cap entry to the sold-out festival for the first time since it began in 1990.

The deteriorating conditions led organizers to announce a “total admission stop” on Wednesday, meaning that only around 60 percent of the 85,000 ticket-holders have been able to enter the event, according to Germany’s dpa news agency.

In a statement posted on the festival’s website, organizers said that “considering the weather conditions, the reasonable visitor capacity for Wacken Open Air 2023 has now been reached.

The 85,000-capacity event had sold out before rain hit.

‘We are very sad, but the continuing difficult weather situation unfortunately leaves us no other choice.”

“Metalheads” with tickets who had not arrived yet were told to turn their cars around and go home.

Videos uploaded on social media show the severity of the situation, with anorak-wearing attendees struggling to wade through ankle-deep mud.

Others chose to embrace the extreme conditions, with one man removing his shirt to nose-dive into the sea of mud, while another lay on his back in the dirt and flailed his limbs.

The muddy conditions have also affected Wacken’s running order, with the start of the festival forced to be postponed. “This meant that six bands could not perform,” a statement on the website said. The festival was set to see 150 bands perform on eight stages over a period of four days.

Iron Maiden, Megadeth and Pennywise are among the bands scheduled to perform at the event, which wraps up on Saturday.

The festival made headlines a few years ago after installing an underground pipeline to bring the hundreds of thousands of liters of beer consumed by revelers to the site.