Valley Rock Festival (also known as VRF, Jisan Valley Rock Festival and Ansan Valley Rock Festival) is held annually on the last weekend of July. Sharing many artists, the festival is arranged by 9 Ent, which is Smash Corporation, and in close coordination with Japanese Fuji Rock Festival. In 2009 on the festival's maiden year, there were some controversies regarding the festival's split from neighboring Pentaport Rock Festival. However the festival's sponsor changed to Mnet media in 2010 and CJ E&M in 2011. VRF has been successful and has grown into one of South Korea's biggest music festivals.