In 2012 - Athens had no recognised Mosque and hundreds of thousands of Muslim immigrants.
The lack of any recognised place of worship was due to many factors - prejudice in favour of the traditional Greek Orthodox faith being the obvious one. The government had actually pledged money for construction of a large mosque just before the financial crisis of 2008. The project was put on hold and every proposed location was dismissed for being 'too prominent' in the Greek community.
This is a study of two makeshift mosques in the city:
"Al Salam" is a Mosque built in an underground parking garage.
"Muslim Hellenic Centre" is the closest thing to a mosque. A 'cultural centre' to promote Greek/Muslim relations. Used mainly as a place of worship.