The 15th Woodstock Festival in Poland

A reveller poses for a picture in front of a giant Woodstock sign during the 15th Woodstock Festival in Kostrzyn-upon-Odra River, close to the Polish and German border, August 01, 2009. (Dalje / javno100)

Revellers dance in front of the main stage during the 17th Woodstock Festival in Kostrzyn-upon-Odra River, Poland, Aug. 6. (Pawel Kopczynski / Reuters)

Revelers play in the mud…

…and enjoy a bungee jump during the 17th Woodstock Festival in Kostrzyn-upon-Odra River, Poland. (Pawel Kopczynski/Reuters)

The 15th Woodstock Festival at Kostrzyn-upon-Odra River, close to the Polish and German border, is a Polish tribute to the original Woodstock festival. (Reuters)

A reveller is lifted in front of the main stage during the 15th Woodstock Festival in Kostrzyn-upon-Odra River, close to the Polish and German border, August 1, 2009. (Dalje / javno100)

Punks walk with beer during the 15th Woodstock Festival at Kostrzyn-upon-Odra River, close to the Polish and German border, August 1, 2009. (Dalje / javno100)

A reveller is lifted in front of the main stage during the 15th Woodstock Festival in Kostrzyn-upon-Odra River, close to the Polish and German border, August 1, 2009. (Dalje / javno100)

An aerial view shows a tent city during the 15th Woodstock Festival in Kostrzyn-upon-Odra River, close to the Polish and German border, August 1, 2009. (Dalje / javno100)

Revellers play in the mud during the 15th Woodstock Festival in Kostrzyn-upon-Odra River, close to the Polish and German border, August 1, 2009. (Dalje / javno100)

A couple enjoy a bungee jump during the 15th Woodstock Festival in Kostrzyn-upon-Odra River, close to the Polish and German border, August 1, 2009. (Dalje / javno100)

A reveller covered in mud attends the 15th Woodstock Festival in Kostrzyn-upon-Odra River, close to the Polish and German border, August 1, 2009. (Dalje / javno100)

Revellers listen to music during the 15th Woodstock Festival in Kostrzyn-upon-Odra River, close to the Polish and German border, August 1, 2009. (Dalje / javno100)

Revellers play in the mud during the annual Woodstock Festival in Kostrzyn-upon-Odra River, Poland. (Reuters)

Festival-goers are covered with the mud during the Przystanek Woodstock Festival near Kostrzyn, Poland. (EPA)