We've seen some very impressive tattoos at Sonisphere festivals over the years, but in particular some of the back pieces have stood out. Here are five back tattoos proudly displayed by festival-goers from all over Europe.

1. Sonisphere Finland, 2010

A true work of art, which had fellow festival-goers reaching for their cameras. He couldn't move anywhere on site without someone snapping away.

2. Sonisphere UK, 2010

This festival-goer was more than happy to reveal his true colours the last time Iron Maiden played Knebworth.

3. Sonisphere Bulgaria, 2010

A dedicated Slayer fan, with guitarist Kerry King etched into his back.

And, yes, here's Kerry King taking a picture of a man with Kerry King tattooed on his back.

4. Sonisphere Spain, 2012

"Daddy you took your broken wings and now you can fly'.

5. Sonisphere UK, 2011

CHECK OUT AWESOME BODY ART WITH US AT SONISPHERE THIS SUMMER