Islam is the fastest growing religion in Western Europe today. As a consequence, the emergence and growth of Muslim religious congregations is one of the most important changes that have taken place within the European third (or voluntary) sector in the last 20 years. However, more often than not, these congregations are described as "enclaves" or "integration traps" isolating new citizens from the rest of society, a picture that has remained largely uncontested due to a lack of more extensive research.