The Effenaar is a pop music venue. It was founded in 1971 and has grown into one of the larger pop venues in the country. The current Effenaar consists of two music halls. The large hall has an audience capacity of 1200, is intended for use by larger bands and acts and is considerably larger than the hall of the original Effenaar. The small hall has a capacity of 350 (which is smaller than the old Effenaar) and is used for smaller and/or regional bands. The old Effenaar has hosted many large (national and international) acts throughout its existence, including The Ramones, U2, The Cure, Joy Division, Sex Pistols, Red Hot Chili Peppers, R.E.M. and Queens of the Stone Age.
The Effenaar was founded in 1971 under the name Open Jongerencentrum (Open Youth center), by young adults with a critical view of society. The Jongerencentrum was established in the abandoned Van den Briel & Verster linen factory; the building was originally renamed “Para+”. The name “Effenaar” is a reference to the old linen factory, which had a machine to remove creases from fabric; in Dutch this is called effenen and the machine was therefore called the effenaar. The Effenaar hosted evenings where young people could express their discontent with society, politics and their parents. After five years the group decided to allow the Effenaar to grow more in the direction of cultural events, but still with criticism of society as the main focus. With time, the group abandoned more and more of its societal role and put more time and effort into putting on musical events. The focus shifted more and more to cultural activities. In 1986 the decision was made to widen the target audience and to make the character of the place more open and welcoming. This attracted a very diverse audience and allowed the Effenaar to grow into the top of the Dutch pop circuit. In order to allow the Effenaar to retain its position in the top, the management decided upon a full renovation, including building a new hall. This building was designed by the Rotterdam architect bureau MVRDV, to be built on the site of the original building; it was completed in 2005. During the building process the old building remained open except for during the last few months.