What starts out as a quiet bike ride for two cyclists through England’s South Downs Way trail quickly turns out to be a trek through an illegal rave.

Through one biker’s GoPro, you can see the bike trail lead to pounding beats, cars and tents, and ravers dancing right in the path of the bikers. According to Metro, the rave started on Saturday night, and police began to receive noise complaints shortly after. At its peak on Sunday, police estimated a crowd of 2,000 with seven sound systems and 400 vehicles. The rave, which seemed to have lasted until Monday morning, was not shut down due to darkness, the rainy weather and lack of available police offers on hand.

Check out the “most underground thing” these cyclists have ever seen in the video below.

Source: Metro